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Purpose: To compare the color dimensions, color discrepancies (E00), and surface roughness of milled materials before and after application of a bleaching agent. Materials and Methods: A total of 10 extracted molars were obtained. Each tooth was cut in transverse sections to create disks (3-mm thick, 10-mm diameter; control group). Disk specimens of eight materials (n = 10 per group) were fabricated: polymethyl methacrylate (PMMA) interim material (PMMA-Telio group), two resin nanoceramics (RNC-Ultimate group and RNC-Cerasmart group), two hybrid ceramics (HC-Shofu group and HC-Enamic group), lithium disilicate (LD-Emax group), zirconia-reinforced glass ceramic (ZGC-Suprinity group), and zirconia (Zr-InCeram group). Color measurements were obtained using a spectrophotometer before and after applying 35% hydrogen peroxide-based bleaching agent. Pre- and postbleaching surface roughness (Sa) analyses were completed using a profilometer. Results: Significant L*, a*, b*, and E00 value differences were found (P < .05). Color discrepancies (E00) ranged from 0.30 ± 0.14 to 4.82 ± 0.10. The highest color discrepancies were measured on the PMMA-Telio group, while the lowest color discrepancies were computed for ZGC-Suprinity, RNCUltimate, and RNC-Cerasmart. Significant surface roughness differences were found (P < .05). The largest increase of surface roughness values between the pre- and postbleaching measurements was obtained in the PMMA-Telio group with a mean Sa value of 4.73 ± 3.02, while the largest decrease of surface roughness values between the pre- and postbleaching measurements was obtained in the Zr-InCeram group with a mean Sa value of -1.58 ± 0.10. Conclusions: The milled materials showed significant pre- and postbleaching color and surface roughness discrepancies. [ABSTRACT FROM AUTHOR]

Successful integration of point-of-care testing (POCT) into clinical settings requires improved assay sensitivity and precision to match laboratory standards. Here, we show how innovations in amplified biosensing, imaging, and data processing, coupled with deep learning, can help improve POCT. To demonstrate the performance of our approach, we present a rapid and cost-effective paper-based high-sensitivity vertical flow assay (hs-VFA) for quantitative measurement of cardiac troponin I (cTnI), a biomarker widely used for measuring acute cardiac damage and assessing cardiovascular risk. The hs-VFA includes a colorimetric paper-based sensor, a portable reader with time-lapse imaging, and computational algorithms for digital assay validation and outlier detection. Operating at the level of a rapid at-home test, the hs-VFA enabled the accurate quantification of cTnI using 50 μL of serum within 15 min per test and achieved a detection limit of 0.2 pg/mL, enabled by gold ion amplification chemistry and time-lapse imaging. It also achieved high precision with a coefficient of variation of

The highly contagious nature and 100% fatality rate contribute to the ongoing and expanding impact of the African swine fever virus (ASFV), causing significant economic losses worldwide. Herein, we developed a cascaded colorimetric detection using the combination of a CRISPR/Cas14a system, G-quadruplex DNAzyme, and microfluidic paper-based analytical device. This CRISPR/Cas14a-G4 biosensor could detect ASFV as low as 5 copies/μL and differentiate the wild-type and mutated ASFV DNA with 2-nt difference. Moreover, this approach was employed to detect ASFV in porcine plasma. A broad linear detection range was observed, and the limit of detection in spiked porcine plasma was calculated to be as low as 42-85 copies/μL. Our results indicate that the developed paper platform exhibits the advantages of high sensitivity, excellent specificity, and low cost, making it promising for clinical applications in the field of DNA disease detection and suitable for popularization in low-resourced areas.

This study aimed to clinically evaluate the effectiveness of two different at-home whitening protocols and to determine which is more effective: applying the whitening gel (16% carbamide peroxide) every 24 hours (Group A) or every 48 hours (Group B) for 2 weeks. Group C received a placebo gel (glycerin) without peroxide, which was applied every 24 hours for 2 weeks. The differences in terms of tooth sensitivity were also analyzed. A sample of 60 patients was divided into three groups of 20 patients. To compare the groups, color measurements were made using a spectrophotometer, and Student t test was used for independent samples. The confidence level was set at 95% (P ≤ .05). No statistically significant differences were found between Groups A and B (P > .05). The study concluded that 16% carbamide peroxide was equally effective when applied with either protocol and obtained the same results, but the 48-hour application protocol produced less sensitivity than the 24-hour application protocol. [ABSTRACT FROM AUTHOR]

This study presents a breakthrough in the field of onsite bacterial detection, offering an innovative, rapid, and ultrasensitive colorimetric biosensor for the detection of Escherichia coli (E. coli) O157:H7, using chemically modified melamine foam (MF). Different from conventional platforms, such as 96-well plates and fiber-based membranes, the modified MF features a macroporous reticulated three-dimensional (3D) framework structure, allowing fast and free movement of large biomolecules and bacteria cells through the MF structure in every direction and ensuring good accessibility of entire active binding sites of the framework structure with the target bacteria, which significantly increased sensitive and volume-responsive detection of whole-cell bacteria. The biosensing platform requires less than 1.5 h to complete the quantitative detection with a sensitivity of 10 cfu/mL, discernible by the naked eye, and an enhanced sensitivity of 5 cfu/mL with the help of a smartphone. Following a short enrichment period of 1 h, the sensitivity was further amplified to 2 cfu/mL. The biosensor material is volume responsive, making the biosensing platform sensitivity increase as the volume of the sample increases, and is highly suitable for testing large-volume fluid samples. This novel material paves the way for the development of volume-flexible biosensing platforms for the record-fast, onsite, selective, and ultrasensitive detection of various pathogenic bacteria in real-world applications.

This work reports a series of yellow-green near-infrared (NIR) reflective pigments, Ba(Mg 6-x-y Zn y Ti 6-x Cr 2x)O 19 (x = 0–1.0, y = 0–2.5), with strong NIR reflectivity for solar thermal energy regulation. Comprehensive analyses were carried out to characterize the obtained pigments including X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, UV–Vis–NIR spectrophotometry, and CIE L*a*b* color measurement. Absorption spectra of Ba(Mg 6-x Ti 6-x Cr 2x)O 19 showed that the yellow-green absorption is attributed to the octahedrally coordinated Cr3+ with d-d electron transitions of 4A 2 (F)→4T 1 (F) and 4A 2 (F)→4T 2 (F). However, their broad absorption peak centered at 1200 nm severely deteriorated the insulating properties of the pigments. Through substituting Mg with Zn, the obtained pigment Ba(Mg 2.5 Zn 2.5 Ti 5 Cr 2)O 19 showed an excellent NIR solar reflectance (R* = 67 %) with color performances (L* = 61.98, a* = −18.72, b* = 22.23). EnergyPlus simulation results show that for a warm city (Haikou), the Ba(Mg 2.5 Zn 2.5 Ti 5 Cr 2)O 19 coating for the external surface of a model house (TSR = 35 %, R* = 55 %) can reduce annual cooling energy consumption by 8 % of the house. [ABSTRACT FROM AUTHOR]

Detecting glucose levels is crucial for diabetes patients as it enables timely and effective management, preventing complications and promoting overall health. In this endeavor, we have designed a novel, affordable point-of-care diagnostic device utilizing microfluidic principles, a smartphone camera, and established laboratory colorimetric methods for accurate glucose estimation. Our proposed microfluidic device comprises layers of adhesive poly-vinyl films stacked on a poly methyl methacrylate (PMMA) base sheet, with micro-channel contours precision-cut using a cutting printer. Employing the gold standard glucose-oxidase/peroxidase reaction on this microfluidic platform, we achieve enzymatic glucose determination. The resulting colored complex, formed by phenol and 4-aminoantipyrine in the presence of hydrogen peroxide generated during glucose oxidation, is captured at various glucose concentrations using a smartphone camera. Raw images are processed and utilized as input data for a 2-D convolutional neural network (CNN) deep learning classifier, demonstrating an impressive 95% overall accuracy against new images. The glucose predictions done by CNN are compared with ISO 15197:2013/2015 gold standard norms. Furthermore, the classifier exhibits outstanding precision, recall, and F1 score of 94%, 93%, and 93%, respectively, as validated through our study, showcasing its exceptional predictive capability. Next, a user-friendly smartphone application named "GLUCOLENS AI" was developed to capture images, perform image processing, and communicate with cloud server containing the CNN classifier. The developed CNN model can be successfully used as a pre-trained model for future glucose concentration predictions. [ABSTRACT FROM AUTHOR]

In this study, a ratiometric fluorescent sensor CdTe QDs@ZIF-8 with butterfly spectra is successfully constructed by in situ encapsulating mercaptopropionic acid-modified CdTe quantum dots in zeolitic imidazolate framework-8 (ZIF-8) with a simple strategy, and used for the detection of tetracycline in fluorescence/smartphone colorimetry dual-mode. ZIF-8 not only reduces the agglomeration of the quantum dots but also surprisingly generates a new green fluorescence signal at 524 nm while the red fluorescence of the CdTe quantum dots at 650 nm quenches when tetracycline is added. The two opposing fluorescence signals create a butterfly-shaped fluorescence spectrum, allowing the sensor to detect tetracycline over a linear range of 0–70 μM with the detection limit (LOD) of 0.0155 μM by using a ratiometric fluorescence technique. What is more, based on the obvious color change of the fluorescent sensor gradually from red to green under UV light, a highly stable point-of-care testing sensor has been developed for on-site detection of tetracycline through color recognition by smartphones, which can be used for real-time detection of this antibiotic in the range of 0–1000 μM with the LOD of 0.0249 μM. This work provides a simple and efficient method for the on-site detection of tetracycline. [ABSTRACT FROM AUTHOR]

Background: White tea, derived from the Camellia sinensis plant like other teas, uses tender buds and young leaves and undergoes minimal processing. This results in higher levels of antioxidants and bioactive substances, which may enhance thermogenesis more effectively than other teas. This first human study aimed to investigate the acute effects of white tea consumption on resting energy expenditure (REE) and some vital signs, including blood pressure (BP), heart rate (HR), and body temperature (BT). Methods: Thirty-two healthy female volunteers with normal initial BP and whose caffeine intakes were < 300 mg/d were enrolled in the study. The caffeine and total phenolic content of white tea samples were determined by the high-performance liquid chromatography method and the Folin-Ciocalteu colorimetric method, respectively. After baseline measurements, participants consumed white tea containing 6 mg of caffeine per kilogram of lean body mass, and the white tea was prepared with bottled drinking water at 80 °C and brewed for 3 min. REE, BP, and BT were assessed at various intervals (baseline, 30 min, 120 min, and 180 min) post-consumption of the white tea. Results: The results revealed a significant increase in REE by 8.7% at 180 min after the consumption. In particular, there was a substantial difference in both values between the intervals of 30 min to 180 min and baseline to 180 min for REE (p < 0.05). Maximal oxygen consumption and BT also increased significantly over time (p < 0.05) and the observed increment in BT suggests a thermogenic effect associated with white tea consumption. However, systolic BP, diastolic BP, and heart rate showed no significant difference. Conclusions: These findings suggest white tea consumption may acutely enhance REE and maximal oxygen consumption, so the results are promising for body weight management. This study is the first human study in the literature about the effects of white tea on energy expenditure and vital signs. [ABSTRACT FROM AUTHOR]

A dual-responsive ratio electrochemical-colorimetric method for nitrite (NO2−) is established based on the combination of nanoenzyme (Mn3O4) catalysis with diazotization reactions. The Mn3O4 can oxidize colorless 3,3′,5,5′-tetramethylbenzidine (TMB) into blue TMBox. The NO2− induces the diazotization reaction of TMBox, leading to a decrease of the signal at 652 nm and the generation of a new signal from diazotized TMBox at 445 nm. Furthermore, the presence of NO2− reduces the electrochemical oxidation signal of TMB and simultaneously provides its electrochemical signal. Compared with traditional single-mode detection, dual-mode detection offers higher sensitivity, lower detection limits, and better interference resistance. The inherent advantages of this method make it feasible to detect NO2− in real samples, offering broad prospects for applications in food safety and environmental monitoring. [ABSTRACT FROM AUTHOR]

Uniform PtCoRuRhFe high-entropy alloy nanoflowers (HEANFs) were fabricated by a simple wet-chemical co-reduction method in oleylamine for quantitative colorimetric determination of captopril (CAP) based on multi-site synergistic signal amplification. Specifically, the peroxidase mimetic activity of the PtCoRuRhFe HEANFs was examined through catalysis of 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation, whose catalytic mechanism was investigated by electron paramagnetic resonance (EPR) spectroscopy. The role of the ·O2− was figured out during the catalytic procedure. Further, the oxidation of TMB (oxTMB) can be effectively reduced by CAP, accompanied by quickly transforming the solution color from blue to colorless. More importantly, the absorbance at 652 nm is linearly related to the CAP concentration in a range 5.0–50.0 mM with a low detection limit of 2.82 mM. The method has been applied to the determination of CAP in human urine samples. It offers a simple and high-efficiency method for facile and visual detection of CAP in hospitals. [ABSTRACT FROM AUTHOR]

Background: Huashi Baidu Formula (HBF) is a clinical formula known for its efficacy against coronavirus disease 2019 (COVID-19). HBF may reduce the number of patients with abnormal serum creatinine while improving respiratory symptoms, suggesting that this formula may have potential for treating acute kidney injury (AKI). However, the protective effect of HBF on AKI has not been definitively confirmed, and the mechanism remains unclear. Therefore, the present study explored the renoprotective effects and molecular mechanisms of HBF and screened for its active ingredients to identify new potential applications of renoprotection by HBF. Methods: The present study first assessed the protective effects of HBF on AKI in a DOX-induced mouse model. Then, RNA-seq and bioinformatics analyses were used to explore the related pathological processes and potential molecular mechanisms, which were subsequently validated using qRT-PCR and Western blotting. Furthermore, candidate compounds with potential binding affinity to two pivotal targets, sphingosine kinase 1 (SphK1) and plasminogen activator inhibitor-1 (PAI-1), were screened from the 29 constituents present in the blood using Microscale Thermophoresis (MST). Finally, to identify the active ingredients, the candidate components were re-screened using the SphK1 kinase activity detection system or the uPA/PAI-1 substrate colorimetric assay system. Results: In the DOX-induced AKI mouse model, therapeutic administration of HBF significantly reduced the levels of CRE, BUN, TNF-α, IL-1β, IL-6, and UA in plasma and the levels of MDA, T-CHO, and TG in kidney tissue. Additionally, the levels of TP and Alb in plasma and SOD and CAT in the kidney tissue were significantly increased. Histopathological assessment revealed that HBF reduced tubular vacuolation, renal interstitial inflammatory cell infiltration, tubular atrophy, and positive staining of renal interstitial collagen. RNA-seq and bioinformatics analyses showed that oxidative stress, the immune-inflammatory response, and extracellular matrix (ECM) formation could be the pathological processes that HBF targets to exerts its renoprotective effects. Furthermore, HBF regulated the APJ/SPHK1/NF-κB and APJ/PAI-1/TGFβ signaling axes and reduced the phosphorylation levels of NF-κB p65 and SMAD2 and the expression of cytokines and the ECM downstream of the axis. Finally, six SphK1 inhibitors (paeoniflorin, astragalin, emodin, glycyrrhisoflavone, quercetin, and liquiritigenin) and three PAI-1 inhibitors (glycyrrhisoflavone, licochalcone B, and isoliquiritigenin) were identified as potentially active ingredients in HBF. Conclusion: In brief, our investigation underscores the renoprotective effect of HBF in a DOX-induced AKI model mice, elucidating its mechanisms through distinct pathological processes and identifying key bioactive compounds. These findings offer new insights for broadening the clinical applications of HBF and unravelling its molecular mode of action. [ABSTRACT FROM AUTHOR]

A colorimetric device is proposed for identifying and detecting the adulteration of various types of starch and flour by diffuse reflection of UV and IR radiation from LEDs. The color characteristics of the samples (RGB channel values) were determined using cameras on OnePlus 10 Pro and iPhone 14 smartphones with installed applications PhotoMetrix PRO, ColorGrab, and RGBer. Near-infrared spectra (4000–10 000 cm–1) were recorded on a Fourier-transform infrared spectrometer. Specialized software packages, including TQ Analyst 9, The Unscrambler X, and XLSTAT, processed the dataset of colorimetric and spectral characteristics. The identification features included clustering patterns for different types of starch and flour in principal component analysis and hierarchical cluster analysis. Optimal wavelengths for determining the quality of adulteration of the tested samples were identified: for starch, the simultaneous use of all LEDs (365, 390, 850, and 880 nm); for flour, LEDs with wavelengths of 365 and 390 nm. The qualitative adulteration was assessed using graphs of the dependence of the F1 component on the mass fraction of the added foreign substance in the starch or flour. The effectiveness of the colorimetric method was confirmed by Fourier-transform infrared spectroscopy in the near-infrared region. [ABSTRACT FROM AUTHOR]

Onosma sintenisii Hausskn. ex Bornm. (O. sintenisii) belongs to the Boraginaceae family and it is an endemic species from Irano-turanian phytogeographical region (central and eastern Anatolia) that distributes in steppe areas. This study aimed to investigate the chemical composition, antioxidant, in vitro cytotoxic and apoptosis induction of methanol extract of aerial parts of O. sintenisii. As a result of GC/MS analysis, 14 components were identified, and the major compounds of the extracts are retronecine (13.94%), α.-D-Glucopyranosiduronic acid (10.86%), melaniline (7.5%) and 1,2-Butanediol (4.02%), respectively. Antioxidant properties of O. sintenisii were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP) and superoxide radical scavenging activity methods. While the DPPH free radical scavenging activity results of O. sintenisii extract varied between 62.49% and 32.27%, reducing power activity and superoxide radical scavenging activity were found to be low. The result of the MTT assay revealed strong anticancer activity of O. sintenisii extract. The most significant cytotoxic effect was noted at a concentration of 1000 µg/mL after 48 hours. These findings together with flow cytometry analysis suggest that apoptosis can be the main mechanism underlying cell death after O. sintenisii extract treatment. [ABSTRACT FROM AUTHOR]

Acidic conditions affect the archaeological bone in the burial and in uncontrolled display and storage environment or due to improper restoration processes. Accordingly, bones become weak and fragile. This study aims to evaluate nano calcium propionate and nano styrene butyl acrylate (used for the first time in the treatment of bones) at different concentrations for deacidification and consolidation of fragile bones. New bone samples were prepared. Artificial accelerated aging (acid and heat) was applied to prepare aged untreated samples. Deacidification and consolidation processes using the materials mentioned above were applied. The analytical techniques used were transmission electron microscope (TEM) and thermal gravimetric analysis (TGA) were used for morphological and thermal stability investigation for the prepared nano styrene butyl acrylate copolymer and its calcium propionate nonocomposites, a digital microscope and scanning electron microscope (SEM) for investigation of the surface morphology, pH value measurement, change of color measurement, attenuated total reflection—Fourier transform infrared spectroscopy (ATR/FTIR), contact angle (wettability), and X-ray diffraction analysis for measurement of bone crystallinity. The results proved that acid-heat aging affected bone properties such as changes in surface morphology and color, decrease in pH value, and contact angle. Bone samples became more crystalline, and the chemical composition of bone was also affected. The treatment of aged untreated bone samples with the materials used in this study improved their properties, such as increasing the pH value and contact angle. The surface morphology, color change, and crystallinity of bone improved and became more stable. [ABSTRACT FROM AUTHOR]

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Road markings (RMs) typically consist of a paint layer and a retroreflective layer. They play a crucial role in road safety by offering visibility and guidance to drivers. Over their lifetime, dirt particles, oils, and greases are adsorbed on the RM surface, reducing their visibility and service life. A self-cleaning ability has been widely studied in several substrates. However, for RMs, this represents a breakthrough and a sustainable advance, while having the potential to increase their service life and enhance road safety. In this context, nanotechnology can be a strong ally through the application of semiconductor materials, such as TiO2, to develop the self-cleaning ability. In addition to this novelty in RMs, quantifying this ability in terms of pollutant removal efficiency is also a challenge. In this sense, artificial intelligence (AI) and colorimetry can be combined to achieve improved results. The aims of the work herein reported were to assess the self-cleaning capability in an RM paint through the mass incorporation of semiconductors, evaluate their photocatalytic efficiency using traditional (spectrophotometric) and modern (AI-enhanced) colorimetry techniques, and compare the results obtained using both techniques. To this end, a water-based acrylic RM paint was modified through the mass incorporation of 0.5%, 1%, 2%, and 3% of nano-TiO2, and a pollutant model widely used, Rhodamine B, was applied onto their surface. The samples were irradiated with a light source that simulates sunlight for 0, 3, 6, 12, 24, and 48 h. Visual analysis and spectrophotometric and artificial intelligence-enhanced colorimetry techniques were used and compared to evaluate the pollutant removal. The results confirm that RM paints with 2% and 3% nano-TiO2 incorporated have a significantly higher pollutant removal ability and that both colorimetric techniques used are suitable for this assessment. [ABSTRACT FROM AUTHOR]

This systematic review evaluated accuracy of ureteric jet angles on color Doppler sonography in diagnosing vesico‐ureteric reflux (VUR) in children, using voiding cystourethrogram as the reference standard. Six databases were searched, yielding 13 eligible studies of an initial 429, 7 with comparable data. Risk of bias and applicability were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS‐2) tool. Most studies demonstrated a correlation between increasing jet angle and VUR severity, but reporting and techniques varied, preventing meta‐analysis. Ureteric jet angle sonography may have potential as a VUR triaging tool. Further investigations with rigorous methodology are required. Funding support was obtained from Queensland University of Technology. PROSPERO Registration CRD42020159799. [ABSTRACT FROM AUTHOR]

This research introduced a microfluidic kit for rapid and economic detection of melamine (MLM) and sodium hypochlorite (NaOCl) in milk samples. The kit allows for simultaneous identification of MLM and NaOCl by reacting with cyanuric acid-modified Au nanoparticles (Au@Ca) and N, N-diethyl-p-phenylenediamine, respectively. The resulting color changes are used as the analytical signal for detection. All of the effective operational parameters were optimized by a one-factor-at-a-time approach. Under the optimum conditions (pH 6.5, path length = 50 mm, flow rate = 0.1 ml/min) a linear relationship between the concentrations of MLM and NaOCl and the blue component of the analyzed RGB pixels of the images captured with a smartphone camera was observed. The linear ranges for MLM and NaOCl were obtained in the concentration ranges of 0.1–1 and 0.1–4.5 µM, respectively, with 0.040 µM and 0.078 µM detection limits, consecutively. The results indicate that the proposed microfluidic kit provides strong selectivity and high reproducibility for detecting MLM and NaOCl in milk samples. To validate the performance of the method, the microfluidic kit was employed for analyzing five different milk samples, yielding recovery values between 94.0% and 105.0% and relative standard deviation values lower than 4.12% indicating the proposed system has admissible accuracy for both analytes. Besides, the results were compared to those obtained using high-performance liquid chromatography, as a standard reference method, and a good agreement between the two approaches was found. [ABSTRACT FROM AUTHOR]

Osmotic drying is commonly utilized to create innovative products, as it can improve the sensory and nutritional qualities of the final products. The present study aims to investigate the effect of different osmotic solutions, including soaking in 1% citric acid, 10% NaCl, and a combination of 1% citric acid and 10% NaCl, as well as different doses of gamma irradiation (1 and 3 kGy), on the quality properties of dehydrated vegetable slices. The chemical composition, mineral content, Color measurement, texture profile, vitamin C levels, and sensory attributes were evaluated for dried vegetable slices. The findings showed that treating vegetable slices with a combination of 1% citric acid and 10% NaCl increased ash (3.43–4.34%), hardness, and total phenolic content (38.37–117.04 mg GAE/100 g). It was the most preferred by the panelists in sensory evaluation scores in comparison to the other treatments. Moreover, there were no significant differences in terms of chemical composition, mineral content, and texture profile analysis between irradiation doses of 1 and 3 kGy. Furthermore, samples irradiated at 1 kGy had significantly higher scores in sensory evaluation compared to both irradiated and unirradiated samples. The current study recommends treating vegetable slices with a combination of 1% citric acid and 10% NaCl before drying to enhance most of the quality attributes of the dried vegetable slices. [ABSTRACT FROM AUTHOR]

4-Chlorophenoxyacetic acid (4-CPA), a synthetic plant regulator, has been banned due to its cumulative toxicity to humans. However, unqualified sampling remains common in the market. To address the poor sensitivity of 4-CPA antibodies reported previously, a highly sensitive monoclonal antibody specific to 4-CPA was produced by redesigning and synthesizing a novel hapten in this study. Additionally, a visual colorimetric immunosensor based on TMB2+ mediated etching of gold nanorods (Au NRs) was developed. The ∆λ of the localized surface plasmon resonance (LSPR) peak exhibited a linear dependence on the 4-CPA concentration in the range of 0.2–6.25 ng mL−1, with a low limit of detection (LOD) of 0.2 ng mL−1. Recovery tests (85.0% to 108%) and HPLC validation demonstrated the immunosensor's accuracy and precision. This visual colorimetric immunosensor illustrates significant potential for rapid detection of 4-CPA in biological environments. [ABSTRACT FROM AUTHOR]

Purpose: Current denture base resins lack adequate strength and antimicrobial properties, necessitating the exploration of alternative solutions. The purpose of this study was to evaluate the effects of curcumin incorporation on the physico-mechanical properties of heat-cured denture base resin, filling a gap in the literature regarding this correlation. Methods: Heat-cured denture base resin was supplemented with increasing concentrations of curcumin (CR). Groups were designated as CR-0 (0%), CR-0.05 (0.05%), CR-0.10 (0.10%), CR-0.50 (0.50%), and CR-1 (1%), based on the increasing concentrations of curcumin incorporated into the material. Physico-mechanical properties, including flexural strength, surface roughness, fracture toughness, impact strength, and color difference, were evaluated following the testing standards. Statistical analysis involved Kruskal-Wallis ANOVA followed by Dunn's test for multiple comparisons, with significance set at P ≤ 0.05 and Bonferroni's correction applied to p-values. Results: Flexural strength peaked at 153.80 MPa in the CR-0.10 group, while surface roughness was lowest at 0.14 micrometers in the CR-0.50 group. Fracture toughness reached its highest value at 1.80 kJ/m^2 in the CR-0.05 group, and impact strength was greatest at 6.52 Joules in the CR-0.05 group. Additionally, color difference was least pronounced in the CR-0.50 group. Flexural strength, surface roughness, fracture toughness, impact strength, and color difference varied significantly among the control group and different curcumin concentrations (P < 0.05). Conclusions: Incorporating curcumin into denture base resin alters both optical and mechanical properties. Further research is required to validate the findings and determine the optimal curcumin concentration without compromising the material efficacy. [ABSTRACT FROM AUTHOR]

ABSTRACT Introduction Materials and Methods Results Conclusions Clinical Significance This study investigated the in vivo color range of human teeth using a research‐grade noncontact spectroradiometer, analyzing the effects of gender, age, ethnicity, and lifestyle factors, including diet, smoking, and oral hygiene.A total of 1004 participants were recruited at two research sites and stratified by gender, age, and ethnicity, and data on their dietary and oral habits were collected. Noninvasive color measurements of an upper central incisor were performed using a spectroradiometer and a fiber‐coupled Xe‐Arc light source. Color differences were computed using the CIELAB and CIEDE2000 color difference formulas, statistically analyzed, and interpreted through comparisons with 50:50% perceptibility (PT) and acceptability (AT) thresholds for dentistry.CIELAB and CIEDE2000 color coordinate values varied significantly. Female teeth appeared lighter and less yellow than men's. Age correlated with darker, more chromatic teeth, stabilizing only after Age 46. Significant ethnic differences were observed, particularly between African‐American and Asian participants. Coffee consumption impacted teeth yellowness and chromaticity, while tea had no significant effect. Frequent tooth brushing led to lighter teeth, and tooth whitening considerably influenced color, emphasizing the effect of cosmetic dental treatments. Smoking showed minimal impact, with slight discoloration noted among light smokers compared to nonsmokers.Color coordinate values by gender, age, and ethnicity exhibited statistically significant differences and, in most cases, noticeable color differences. With exceptions, the dietary/oral habits of the patient had a significant impact on the color of human teeth.The findings from this study provide detailed information and understanding of the color range and distribution of human teeth, which can help enhance the esthetic outcome of dental care and, consequently, the patient's satisfaction. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Materials and Methods Results Conclusions Clinical Significance To examine the effects of six whitening mouthwashes on tooth color and immediate bond strength to the enamel.Human incisors were divided into seven groups (n = 10) according to mouthwashes (R.O.C.S Black Edition White, Splat White Plus, Colgate Plax White Charcoal, Signal White Now, Listerine Advanced White, Colgate Optic White, and distilled water). After the initial color measurements, the teeth were exposed to mouthwash for 4 weeks. Then, the color measurements were repeated. Then, cylindrical composite resin blocks were immediately applied to the enamel surfaces and subjected to shear bond strength tests. Data were analyzed using Kruskal‐Wallis and Bonferroni tests (α = 0.05).Δ푏, Δ퐿, and ΔE00 values did not present significant differences among the groups. Significant differences among the groups were determined for Δ푎 and ΔWID values (p < 0.05). R.O.C.S Black Edition White and Splat White Plus produced clinically acceptable color changes. Signal White Now, Splat White Plus, and Listerine Advanced White created acceptable whiteness changes. The mouthwashes did not statistically affect the bond strength compared to the distilled water (p > 0.05).Whitening mouthwash containing blue covarine revealed more acceptable color and whitening changes. Mouthwash containing charcoal led to the lowest enamel bond strength values.The content of whitening mouthwashes affected the degree of tooth whitening and shear bond strength to enamel. [ABSTRACT FROM AUTHOR]

AbstractAccurate, rapid, and quantitative detection of D-penicillamine (D-PA) in pharmaceutical formulations is imperative for drug quality and clinical medication guidance. Various colorimetric and fluorescent assays have been constructed for D-PA based on nanomaterials. However, the reliable and rapid detection of D-PA in pharmaceutical formulations remains a challenge because these methods suffer from shortcomings such as time-consuming procedures, poor uniformity, and complicated nanomaterial preparation. In this work, an effective and facile homogeneous dual-mode optical sensing strategy was established based on the strong complexation between D-PA and Cu2+ and catalyzed the oxidation of O-phenylenediamine. This platform displayed a sensitive response to D-PA from 5 to 100 µmol/L, with a detection limits of 0.54 µmol/L (fluorescence) and 0.76 µmol/L (colorimetry). As expected, the method was successfully applied to the determination of D-PA in pharmaceutical formulations with satisfactory results. Overall, this developed strategy provides a facile and rapid dual-mode optical platform for D-PA and has great potential in D-PA-related pharmaceutical quality control. [ABSTRACT FROM AUTHOR]

The bovine lungworm, Dictyocaulus viviparus (Bloch, 1782), is highly pathogenic and disease outbreaks can be difficult to predict and manage. Rapid and accurate diagnosis is vital, but without a sensitive diagnostic test this remains challenging in clinical practice. High performance molecular detection tools are therefore required to improve the diagnosis of this parasite and promote the implementation of strategic control measures. Loop-mediated isothermal amplification (LAMP), a rapid DNA assay, offers potential for field-based detection. Here we report a novel LAMP assay (DviLAMP), that was designed to target the D. viviparus internal transcribed spacer 2 (ITS2) ribosomal DNA region. Firstly, genomic DNA was extracted from a single D. viviparus L1 larva to amplify and clone the ITS2 into the recombinant plasmid (DviITS2). The DviLAMP successfully detected the target, with results shown by gel electrophoresis and real-time analysis, in addition to point-of-care amenable end-point detection: colorimetry and lateral flow dipstick (LFD). Analytical sensitivity can detect 0.5 ng DviITS2 following 45 min of incubation at 64°C, increasing to just 1 pg following 90 min of incubation. Using the same primers, other nematodes of cattle, Ostertagia ostertagi and Cooperia oncophora, were also detectable both by gel electrophoresis and real-time. However, when FITC and biotin tagged primers were incorporated to adapt the DviLAMP to LFD end-point detection, the LFD showed specific detection of D. viviparus. Further development of DviLAMP as a point-of-care test could significantly improve the sensitivity of lungworm diagnosis in the field. [ABSTRACT FROM AUTHOR]

The longevity and acceptance of aesthetic dental materials are directly proportional to color stability. The aim of this study was to analyze the relationship between the use of multivitamins and the color stability of dental restorative materials. A total of 45 discs of nanohybrid composite, 45 of Reinforced Glass Ionomer (RGI), and 45 of Giomer were prepared. Subsequently, the samples were randomly divided into three solution groups (n = 15): Group 1—Sambucol Pediatric Syrup, Group 2—Hidropolivital Baby Drops, and Group 3—artificial saliva, which is preparation for patients with xerostomia. For 28 days, the specimens were immersed in 10 mL of each multivitamin for two minutes every 24 h. Color measurements were repeated on days 7, 14, 21, and 28. Statistical analysis was performed using the Jamovi software version 2.2.5, employing the Shapiro–Wilk test for normality and the Kruskal–Wallis test for non-parametric data. When comparing materials, statistically significant differences (p < 0.001) were observed between RGI and Giomer, and RGI and composite, but not between Giomer and composite (p = 0.716). The highest change was observed in RGI–Hidropolivital ΔE00 = 3.27 (2.38–4.59) and the least in composite–Sambucol ΔE00 = 0.72 (0.30–1.18). In conclusion, the exposure time and the multivitamin influence the color change of restorative materials. [ABSTRACT FROM AUTHOR]

Anthropogenic lead pollution remains a serious environmental concern due to the high incidence of human exposure worldwide and its severe health impact, particularly to children. We report a device-free colorimetric sensor for lead(II) ions in water based on the microdrop detection of the lead(II) rhodizonate complex trapped into a solid-solution of cellulose paper. This allows for the selective colorimetric detection of Pb2+ with a qualitative and quantitative detection limit of ~ 1 ppm. Comparative studies with Li+, Na+, K+, Ca2+, Mg2+, Sr2+, Ba2+, Cd2+, Ni2+, Cu2+, Zn2+, Fe2+, Hg2+, Co2+, Ce2+, Mn2+, Cr2+, Cr2+, and Au3+ show high detectability for Pb2+ due to the unique charge transfer band present in the kinetically trapped Pb-RA complex. We demonstrated that without the solid-solution matrix, the lead(II) rhodizonate complex polymerizes into an extended solid. The mechanism and kinetics of Pb2+ detection were studied by UV-visible spectroscopy, XRD, transmission electron microscope (TEM), and dynamic light scattering analysis (DLS). This device-free sensing method for Pb2+ is highly portable and suitable for applications on the field. [ABSTRACT FROM AUTHOR]

Plants such as herbs, vegetables, fruits, and cereals are closely related to human life. Developing effective testing methods to ensure their safety and quantify their active components are of significant importance. Recently, nanomaterials with enzyme-like activity (known as nanozymes) have been widely developed in various assays, including colorimetric, fluorescence, chemiluminescence, and electrochemical analysis. This review presents the latest advances in analyzing phytochemicals and hazardous substances in plant samples based on nanozymes, including some active ingredients, organophosphorus pesticides, heavy metal ions, and mycotoxins. Additionally, the current shortcomings and challenges of the actual sample analysis were discussed. [ABSTRACT FROM AUTHOR]

Color of wine gives information on many aspects of the product, and it is one of the main parameters defining wine quality. Consequently, color is an important attribute described in the Designations of Origin (PDO)'s technical specifications. In this paper, color reference grids for color sensory evaluation of white, rosé and red wines (linked to a specific methodology and controlled illumination) are developed, presented, and validated. The color intensity and color hue parameters of 2353 wines of different types have been analyzed using these reference grids during the period 2021–2023. Considering the results obtained, the usefulness of having a double color measurement (color intensity and color hue) is questioned and discussed. [ABSTRACT FROM AUTHOR]

Heavy metal contamination especially in aqueous media has become an important risk to human health and environment. Therefore, due to the broad distribution of barium (Ba2+) and strontium (Sr2+) ions in the environment and wide variety of their harmful health effects for human, development of efficacious systems for their accurate and selective determination is of great importance. Aiming to develop a point-of-care and easy-to-use sensing device, a paper-based colorimetric sensing device was designed for simultaneous measurement of Ba2+ and Sr2+ ions standing on the basis of the color change of sodium rhodizonate (SR) in the presence of various concentrations of the target analytes. These color changes were photographed using a smartphone, and after analyzing with Photoshop 2022 software, the average variations in the intensities of colors (RGB (red, green, blue) model) were used to draw the calibration curves. The quantitative identification of Ba2+ and Sr2+ ions in a single solution was carried out by masking one of them at a moment. The average color intensities (G) displayed a linear relationship with the concentration of the analytes in the ranges of 5––300 ppm and 5–350 ppm with the limit of detection (LOD) values of 3.64 and 4.75 ppm for Ba2+ and Sr2+ ions, respectively. Moreover, the selectivity of the proposed analytical device was assessed; SR was selective for the target analytes versus the other ions causing a considerable color change. Furthermore, the practical application of this colorimetric device was investigated by the excellent performance in real samples indicating its potential for field applications. [ABSTRACT FROM AUTHOR]

The conditions for the smart colorimetric determination of cetylpyridinium chloride and sodium dodecyl sulfate by reaction with Coomassie brilliant blue G (CBBG) have been proposed. The nature of the absorption and fluorescence spectra of aqueous solutions of CBBG as a function of acidity has been investigated. A variety of reagent forms and associations with ionic surfactants have been demonstrated. The composition of the associates formed in the CBBG–cationic surfactant system has been established. The increase in the analytical signal of the cationic surfactant and the stabilization of the colloid-chemical state of the system during reactions in the organized medium of the nonionic surfactant Triton X-100 has been demonstrated. These effects are realized through association in premicellar solutions and as a result of the solubilization of components in Triton X-100 micellar solutions. The addition of long-chain cationic surfactants to the reagent occurs with the replacement of the heteroatom proton. The absorption of CBBG–cationic surfactant associates solutions increases with the length of the cationic surfactant hydrocarbon chain. Ethanol additives decrease the aggregation of CBBG. The technique of cationic surfactant determination has been tested in the analysis of the pharmaceutical. The results show that the simplicity of analytical signal registration with satisfactory correctness and acceptably high sensitivity of determination is an advantage of the developed technique. [ABSTRACT FROM AUTHOR]

Immunoassays have been widely used for the determination of various analytes in the fields of disease diagnosis, food safety, and environmental monitoring. Dual-signal immunoassays are now advanced and integrated detection technologies with excellent self-correction and self-validation capabilities. In this work, we summarize the recent advances in the development of optical and electrochemical dual-signal immunoassays, including colorimetric, fluorescence, surface-enhanced Raman spectroscopy (SERS), electrochemical, electrochemiluminescence, and photoelectrochemical methods. This review particularly emphasizes the working principle of diverse dual-signal immunoassays and the utilization of dual-functional molecules and nanomaterials. It also outlines the challenges and prospects of future research on dual-signal immunoassays. [ABSTRACT FROM AUTHOR]

Pesticide residues seriously impact food safety and environmental protection. Consequently, there is a pressing demand for the development of dependable and efficient methods for pesticide residues detection. In recent years, optical aptamer sensors have emerged as highly sensitive and fast-response sensing platforms for pesticide detection. These developed sensors rely on the selectivity and sensitivity of nucleic acid aptamer to specifically interact with the target pesticide, resulting in an observable signal response. Various optical aptamer sensors such as fluorescence, colorimetry, surface-enhanced Raman scattering (SERS) methods, and chemiluminescence (CL) methods have been effectively employed for accurate and rapid detection of pesticides, encompassing a range of pesticide types including insecticides, fungicides, and herbicides. These sensors offer several advantages including quick response times, high selectivity and sensitivity, user-friendly operation, and enabling real-time monitoring. This paper provides a comprehensive review of recent advancements in the application and development of optical aptamer sensors for pesticide residue assay with the overarching goal of furnishing an invaluable reference point for forthcoming research and advancements in the realm of swift and highly sensitive pesticide residue detection. [ABSTRACT FROM AUTHOR]

The aim of this study was to design and assess composite resin composition for patient-specific esthetic color-graded temporary veneer. Various compositions of composite structures (assorted by Ba 2 SiO 4 filler, TiO 2 pigment, and photoinitiator) were prepared via additive manufacturing with 3 s UV exposure (405 nm, 10 W/cm2) per 50 µm thick layer followed by 20 min post-curing treatment after fabrication. The effect of each component on the generated color shades was observed and compared to the commonly used VITA shade guide. The coloration was explored by staining aging treatment under dry, wet, artificial saliva environments, coffee, and cola. The mechanical properties were also evaluated. Color measurement and comparison were done using a colorimeter (lightness (L*), green-red color (a*), and blue-yellow color (b*)), and the changes were calculated by CIEDE2000 (ΔE 00), translucency parameter (TP) and whiteness index (WI D). The composition color analysis results were then applied to produce a color-graded temporary veneer for mimicking a natural look. Mechanically, all composition result in adequate bending strength with maximum achievable strength of 111.64 MPa. At the same time, the composite color was affected by each constituent differently. The L* value, which indicates the color lightness of the composite, was considerably tuned by the TiO 2 pigment, whereas Ba 2 SiO 4 filler only triggered minor changes. Photoinitiator concentration significantly affected the yellowness, indicated by the increased b* value. Similar tendency also observed toward the calculated TP and WI D as well. Based on these evaluations, color-graded temporary veneer successfully generated, matching the VITA A3, A2, and B1 shades gradation. However, the stability of the composite color decreased at high amounts of Ba 2 SiO 4 and photoinitiator. The study presents a composition guide for fabricating temporary patient-specific color-graded veneer. It provides insights on the effect of the constituent material on dental esthetics. [Display omitted] • Practical use of functionally graded AM (FGAM) for esthetic composites veneer. • Customized composites (varying filler, pigment, photoinitiator) for dental implant • Improved esthetics, mimicking natural teeth, achieved via composition control • High strength and stain resistance composites comparable to conventional implants [ABSTRACT FROM AUTHOR]

The calligraphy on Xuan paper written by Cao Hongxun, who was a scholar at the end of the Qing Dynasty, was comprehensively characterized using various analytical techniques in order to provide support for further conservation. Fourier transform infrared (FTIR) spectroscopy was used to identify the type of oil in the stains. The color difference, acidity, microstructure and elemental composition of the paper areas with and without the oil stains were analyzed and characterized using colorimetry, pH measurements, and scanning electron microscope-energy dispersive spectrometry (SEM-EDS), respectively. Paper fibers were observed using SEM and an optical microscope after dying with Herzberg stain. The results demonstrate that the stain in this paper artifact is mineral oil and the paper was produced using softwood, paper mulberry and herb fibers. A large color difference, lower pH and changes in the carbon ratio were present in the oil stains. However, the stains did not affect the elemental composition of the paper. Overall, this study provides evidence for further conservation treatment, such as selecting proper paper and cleaning reagents for the stains. [ABSTRACT FROM AUTHOR]

A colorimetric and rapid signal amplified microRNA (miRNA) detection system based on autocatalytic entropy-driven circuit (AEDC) is reported. The target miRNA-21 (miR-21) was firstly hybridized with the sticky end of the triple-stranded hybrid complex (S, which consisting of a reporter strand (P), a byproduct strand (R) and an assistant strand (Q)), and P strand, which contained the G-quadruplex sequence that was released through the toehold-mediated strand displacement reaction. The G-quadruplex sequence interacted with hemin to form the peroxidase-mimicking DNAzymes and catalyzed the H2O2-mediated oxidation of colorless 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS2−) to the green ABTS•−. Meanwhile, fuel strand (F) hybridized with S to release the target miR-21 and the waste duplex DNA product F-Q was formed, which brings the two split mimic target DNA sequences into proximity to form the intact mimic target DNA sequence (analogue of miR-21). The obtained mimic target DNA as well as the released miR-21 can be cyclically used to trigger autocatalytic EDC reaction, leading to the rapidly enhanced formation of mimic target DNA with the concomitant generation of a higher colorimetric signal. Finally, a colorimetric and rapid miR-21 system based on the hairpin-free AEDC reaction was successfully fabricated. This system also has been applied for the miRNA determination in serum, exhibiting the potential application in the clinical diagnosis. [ABSTRACT FROM AUTHOR]

The study aims to evaluate the performance of Vitamin D/calcitriol-induced miR-589-3p in predicting the prognosis of cervical cancer patients and its role in cancer cell function. To identify differentially expressed miRNAs (DEMs) related to calcitriol treatment, the GSE61829 dataset was analyzed. MiR-589-3p expression levels were verified in cervical cancer patients. The association of miR-589-3p with overall survival was investigated using Kaplan-Meier survival analyses and the multi-variate Cox proportional hazards model analysis. The effects of miR-589-3p on cervical cancer cells and calcitriol-treated cells were examined using the MTT assay and Transwell migration/invasion assay. From GSE61829 dataset, a total of eleven DEMs were identified, including miR-589-3p. MiR-589-3p was found to be decreased in cervical cancer but increased after one-year intake of Vitamin D. Low miR-589-3p after one-year intake of Vitamin D was identified as a predictive factor for low survival probability (p = 0.0059) with a significant impact on the death risk (HR: 3.04; 95%CI: 1.47-6.29; p = 0.003). MiR-589-3p overexpression inhibited the proliferation and migration/invasion of cervical cancer cells and calcitriol-treated cervical cancer cells. In conclusion, miR-589-3p can be induced by Vitamin D/calcitriol treatment and inhibit cervical cancer progression. MiR-589-3p has the potential to predict overall survival in patients with cervical cancer. [ABSTRACT FROM AUTHOR]

Saffron (Crocus sativus L.) is cultivated in environments with very different climatic conditions and with very different corm rates from place to place, and it is appreciated for its red dried stigmas used as cooking spice and flavoring agent. To enhance the flower morphological and colorimetric traits under environmental stresses, the applications of non-thermal plasma based techniques are increasingly being investigated in the field of agricultural science as an alternative to conventional pre-germination treatments. Therefore, a field study was conducted to compare four levels P1 (no treatment), P2 (5 minute treatment), P3 (10 minute treatment), P4 (20 minute) and the salinity stress factors in three levels were 2, 4 and 6 dS.m-1 according a factorial design with 3 replications. Flowering beginning in saffron seems to be influenced by the combination of plasma and salinity stress. High concentration of salinity (6 dS.m-1) resulted in a lower flower and stigma production. The highest number of leaf per plant was found when corms treated to P4 and 2 dS.m-1 6 salinity stress condition. Exposure of saffron corn to plasma treatments of 20 minutes showed the most stimulating effect regarding the flower phenology and stigmas yield in saffron under salinity stress. [ABSTRACT FROM AUTHOR]

Ceramic dental restorative materials have growing popularity, albeit their brittle and stochastic nature are acknowledged shortcomings that impact the prosthesis lifespan. The mechanical performance of ceramics is dominated by the constitutional microstructural and fracture toughness mechanisms, as well as externally applied triggers. Thus, there is ongoing expanding research in the sphere of ceramic material engineering and thermal refinement, addressing concerns regarding toughness, machinability, reliability, stainability, and biodegradation. While the current trend in dental ceramic manufacturing has transitioned from micrometric crystalline sizes to submicrometric and nanometric ranges, there is an unclear understanding of the microstructural implications on ceramic behaviour. Therefore, this review covers the comprehensive characterisation approaches commonly employed in the scientific literature to describe the multifaceted performance aspects as well as clinical-related prerequisites of dental ceramics. Moreover, updated standardised testing parameters and performance thresholds pertaining to ceramic mannerisms are described in an attempt to translate their clinical applicability. [ABSTRACT FROM AUTHOR]

We suggest sensor systems based on silver nanoparticles embedded within the polymethacrylate matrix for colorimetric determination of hydrogen peroxide. Polymethacrylate matrix stabilizes silver nanoparticles and its application enhances the selectivity of H2O2 determination through the transfer of the redox reaction from the solution volume into the solid phase, which reduces the access of interfering substances to the reaction medium. Dual-signal spectrophotometric and colorimetric approaches can be used for the determination of hydrogen peroxide in the range 0.2–4.4 mM with a detection limit 0.05 mM. We studied the conditions of interaction between the matrix components and some other substances by evaluating the influence of such factors as solution pH, the amount of nanoparticles within the polymer matrix, the contact time, and the analyte concentration upon the analytical signal. [ABSTRACT FROM AUTHOR]

Nanozymes‐involving colorimetry may represent an effective solution to tetracycline detection due to its affordability and simplicity. To improve the performance in selectivity, molecular imprinting technology has emerged as a promising approach to simulating the interaction between antibodies and receptors. Herein, Mn2V2O7, a form of nanozyme with oxidase‐mimicking activity, was synthesized. With tetracycline as the template, the cavities with unique dimensions were constructed through the self‐polymerization of dopamine (DA) on Mn2V2O7. In Mn2V2O7@MIP, polydopamine (PDA) acts as molecularly imprinted polymer (MIP) and its cavities are compatible with tetracycline in dimension. It also exhibits oxidase‐mimicking activity. With the introduction of tetracycline, the cavity of PDA is blocked, which leads to obvious color fading, which enables precise tetracycline detection with colorimetry. The range of linear detection is from 10 to 100 μM, and the lower limit of detection is 0.82 μM. It is anticipated that the combination between nanozymes‐involving colorimetry and molecular imprinting technology would contribute to the accurate detection of organic pollutants in the aquatic environment. [ABSTRACT FROM AUTHOR]

A method of digital colorimetric determination of ammonium and nitrate in soils is proposed. The method is based on corresponding photometric procedures of ammonium and nitrate determination after potassium chloride extraction from soil samples. Ammonium is determined as an indophenol dye, and nitrate is determined as an azo dye. The original procedures were modified to overcome the lower sensitivity of the digital colorimetric method. For ammonium determination, the time required for the reaction to proceed completely was studied. Along with the use of a 96-well microplate protected from ambient light by a special frame, mathematical correction of scattered radiation using black ink and taking the images by a scanner in transmission mode without any post-processing, the resulting colorimetric methods proved to provide accuracy and sensitivity close to those of the spectrophotometric method, and the overall analysis speed for tens of samples was even higher. Limits of detection and quantitation for NO3– were 0.42 and 1.4 mg/kg, and for NH4+, they were 1.1 and 3.7 mg/kg, which is lower than for standard methods. The methods' validity was proven by the analysis of standard samples and by the analysis of soil samples collected in several districts of the Moscow region. [ABSTRACT FROM AUTHOR]

Driven by their exceptional optical characteristics, robust chemical stability, and facile bioconjugation, gold nanoparticles (AuNPs) have emerged as a preferred material for detection and biosensing applications in scientific research. This study involves the development of a simple, rapid, and cost-effective colorimetric immuno-sensing probe to detect aflatoxin B1 and zearalenone using AuNP antibody (AuNP-mAb) conjugates. Anti-toxin antibodies were attached to the AuNPs by using the physical adsorption method. The colorimetric immunosensor developed operates on the principle that the optical properties of the AuNP are very sensitive to aggregation, which can be induced by a critical high salt concentration. Although the presence of antibodies on the AuNP surface inhibits the aggregation, these antibodies bind to the toxin with higher affinity, which leads to exposure of the surface of AuNPs and aggregation in a salt environment. The aggregation triggers a noticeable but variable alteration in color from red to purple and blueish gray, as a result of a red shift in the surface plasmon resonance band of the AuNPs. The extent of the shift is dependent on the toxin exposure dose and can be quantified using a calibration curve through UV–Visible–NIR spectroscopy. The limit of detection using this assay was determined to be as low as 0.15 ng/mL for both zearalenone and aflatoxin B1. The specificity of the prepared immunoprobe was analyzed for a particular mycotoxin in the presence of other mycotoxins. The developed immunoprobe was evaluated for real-world applicability using artificially spiked samples. This colorimetric immunoprobe based on localized surface plasmon resonance (LSPR) has a reduced detection limit compared to other immunoassays, a rapid readout, low cost, and facile fabrication. [ABSTRACT FROM AUTHOR]

The research and development of green techniques for the synthesis of silver nanoparticles (AgNPs) with bioactive plants has gained more attention against toxic chemicals. In this research, the aqueous solution of safflower extract was utilized for the simple, green, and commercial synthesis of AgNPs from AgNO3 solution on the wool yarn. The effect of the amount of extract and AgNO3 on the properties of produced nanoparticles was studied. The analysis of AgNPs by Dynamic Light Scattering (DLS) system and Ultravioletvisible (UV-Vis) spectroscopy exhibited that the particle size of produced NPs was <57 nm. In addition, the colorimetric data of wool yarn dyed with safflower extract in the presence of different concentrations of AgNO3 solution were also studied. The results showed that the presence of nanoparticles changed the color hue (hᵒ: 86→58), and the absorption of safflower extract on the wool samples increased from 5 to 29. Also, the ratings of washing and rubbing fastness of dyed samples were satisfactory (4-5). [ABSTRACT FROM AUTHOR]

Objectives: This study aims to evaluate the color‐matching ability of OMNICHROMA composite, a single‐shade composite, using the CIE L∗a∗b∗ system and determining ΔE values. Materials and Methods: In this in vitro study, 30 intact premolar teeth were collected, cleaned, and disinfected with 0.5% thymol solution. The teeth were stored in distilled water at 37°C. A putty index calibrated the color assessment sites on buccal and lingual surfaces. Two cavities were prepared, one with 1.25 mm depth (enamel) and another with 2.25 mm depth (dentin), and restored using OMNICHROMA composite resin. The putty index measured the color of the cured composite, and ΔE between the composite and original tooth color was calculated. Statistical analysis: Data analysis included t‐tests, correlation coefficients, and Fisher's exact test (α = 0.05). Results: The mean ΔE was 2.39 in enamel cavities and 2.32 in dentin cavities, both within the clinically acceptable range (<3.3). In enamel cavities, the composite color was darker than the tooth, shifting toward green and blue shades. In dentin cavities, the composite color was lighter than the tooth, with shifts toward green and yellow shades. Color matching was slightly better in dentin cavities, but the difference was not statistically significant (p = 0.719). Conclusion: OMNICHROMA composite resin's color matching falls within the clinically acceptable range, unaffected by cavity depth. [ABSTRACT FROM AUTHOR]

Electrochemical (EC) analysis has emerged as a high‐sensitivity, reliable, cost‐effective, and rapidly evolving technique that has garnered significant attention across diverse domains. Furthermore, EC‐based techniques hold great potential for miniaturization and integration. The integration of EC techniques with diverse mode/signal (such as light, magnetic, and thermal signals, etc.) provides unique opportunities for biosensors to acquire more information through a single sensing platform. By coupling multiple signals or processing them logically, the detection accuracy can be further improved, and the probability of false positives or negatives can be minimized. In this review, a thorough analysis of multi‐ mode/signal sensors in the field of EC sensing is conducted, along with their integration with various sensing techniques (e.g., fluorescence, photothermal, colorimetry, microfluidic, etc.). The aim is to delve into the latest advances, potential applications, as well as challenges in multi‐mode/signal biosensors, where the utilization of multiple sensing modalities helps enhance accuracy, sensitivity, and selectivity. This review provides new insight into the synergistic effects of integrating EC sensing with other techniques, aiming to shed light on the near‐future developments in EC‐integrated multi‐mode/signal biosensors. [ABSTRACT FROM AUTHOR]

Dopamine (DA) is a potent neuromodulator in the brain that affects a wide range of motivated behaviors. Abnormal concentration of DA is related to a variety of diseases. Hence, it is imperative to establish a rapid and precise method for quantifying DA. In this work, we integrate orange-yellow emissive carbon dots (CDs) with target-induced silver deposition on gold nanoparticles (Au NPs), forming gold/silver core-shell nanoparticles (Au@Ag NPs), to construct a fluorometric and colorimetric dual-signal sensor for sensitive detection of DA. Au NPs and silver ions (Ag+) have minimal effect on the fluorescence of CDs. DA can reduce the silver ions to Ag(0) on the surface of the Au NPs to form a silver shell, resulting in the blue-shift of the absorbance peak from 520 to 416 nm, which overlaps with the excitation spectrum of CDs. As a result, the system color turns from pink to orange-yellow, and the fluorescence of CDs is quenched due to the strong inner filter effect. The linear range of the colorimetry is 0.5–18 μM with a limit of detection (LOD) of 0.41 μM, while the linear range for the fluorometry method is 0.5–14 μM with a LOD of 0.021 μM. This method demonstrates notable advantages including a low detection limit, rapid response time, and straightforward operation in practical samples, showing great potential in biomedical analysis. [ABSTRACT FROM AUTHOR]

Background: This study proposes a simple digital image colorimetric method using a smartphone for the quantitative analysis of isoniazid in pharmaceutical medications. The analytical methodology employed in this study involved the utilization of the reaction between isoniazid and FC reagent under alkaline conditions. The chemical reaction led to the creation of a complex with a blue-gray color, exhibiting a peak absorption at a wavelength of 760 nm. An Android application was employed to perform a smartphone-based determination based on separating the captured color into different color channels such as red, blue, green, etc. The experimental procedure involved the utilization of three smartphones for the determination, which was subsequently followed by a comparative analysis of the results obtained from these devices using spectrophotometric measurements. Results: The B channel had the highest level of optimization in terms of analytical parameters. The limits of detection (LOD) were 0.586, 2.478, and 1.396 µg/ml for S1, S2, and S3, respectively, and for the spectrophotometer, it was found to be 0.416 µg/ml. Similarly, LOQs were determined as 1.673, 7.511, 4.232, and 1.302 µg/ml. A %RSD of 1.3 for precision and an LOD of 0.013 g dm−3 were obtained for the spectroscopic method. The % recovery in the accuracy study was found to be 99.69, 101.804, 109.28, and 100.13 for S1, S2, S3, and spectrophotometer, respectively. Conclusion: The colorimetric results from smartphone application are similar to those from spectrophotometric analyses. [ABSTRACT FROM AUTHOR]

The organic photoelectrochemical transistor (OPECT) biosensing relies solely on a singular signal readout inherently, which restrains the precision and dependability nestled within pertinent biological measurements. Herein, a high‐precision magnetic assisted OPECT and smartphone colorimetric (SCL) dual‐mode biosensing platform is first established for detecting harmful algal toxin okadaic acid (OA) by biocatalytic reaction. MXene@SnO2‐Ce‐MOF (MXSnO/Ce‐MOF) Z‐scheme heterojunctions with abundant oxygen vacancies are prepared as photoactive materials. Initially, in the presence of OA, the coupling of trigger DNA (tDNA) to magnetic beads (MBs) via anchor DNA (aDNA) is released through the interaction of the target analyte with the aptamer. Subsequently, the carried tDNA triggers HCR between the two hairpin sequences, producing long double helix chains to capture glucose oxidase (GOx). The obtained GOx supernatant catalyzes glucose to produce H2O2, which can oxidize Ce‐MOF, leading to the alteration of electrode color and a significant decrease in the overall photocurrent of MXSnO/Ce‐MOF. Crucially, the novel OPECT‐SCL biosensor exhibits excellent sensitivity and precision, boasting detection thresholds as low as 42.9 pM and 1.2 nM, respectively, and accomplishes the automated detection of OA within real samples. The proposed OPECT‐SCL dual‐signal measurement model constitutes a sensitive, portable, and precise platform for the quantification of marine toxins. [ABSTRACT FROM AUTHOR]