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[Display omitted] • A simple and portable photothermal method for biothiols was designed. • The polydopamine nanoparticles with photothermal effects were formed on the surface of ZIF-67. • Biothiols could "weaken" the photothermal signal through decomposition of ZIF-67. • The proposed sensor possessed high sensitivity and specificity for biothiols. • Satisfactory analytical results in fetal bovine serum suggests the sensor's applicability. Abnormal levels of biothiols such as cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) are associated with many pathological diseases. The demand for bulky and costly apparatuses represents a big impediment for point-of-care testing of biothiols. Herein, we developed a novel photothermal sensor for biothiols based on the formation of polydopamine nanoparticles (PDA NPs) using a thermometer as readout. A zeolitic imidazolate framework (ZIF-67) was first fabricated through a facile one-pot strategy. Then dopamine (DA) was immediately polymerized into PDA NPs with excellent photothermal effects (PETs) in the presence of the ZIF-67. Biothiols could disintegrate ZIF-67 by substituting ligands, causing the reaction between biothiols and cobalt ions to form complexes, and release 2-methylimidazole (2MIM) that can slowly oxidize DA, thereby "weakening" the PETs signal, which enabled us to convert biological signals into temperature signals. Therefore, the quantitative detection of Cys, Hcy and GSH can be achieved by recording temperature changes, with detection limits as low as 0.158 μM, 0.181 μM and 0.207 μM, respectively. Furthermore, the photothermal sensor has been applied in detection of biothiols in fetal bovine serum with satisfactory recovery rates, correlating well with the results by standard Ellman method, signifying its promising potential in integrated biological detection system. [ABSTRACT FROM AUTHOR]

Background: HTLV-1 and HTLV-2 are retroviruses linked etiologically to various human diseases, and both of them can be transmitted by vertical route, sexual intercourse, blood transfusion and intravenous drug use. Recently, some HTLV-infected cases have been reported and this virus is mainly present in the Southeast coastal areas in China, but has not been studied for the people in Central China. Objectives: To know the epidemiologic patterns among different population samples in Central China and further identify risk factor for HTLV-1 and HTLV-2 infection. Methods: From January 2008 to December 2011, 5480 blood samples were screened for HTLV-1/2 antibodies by using enzyme immunoassay, followed by Western Blot. Results: The prevalence of HTLV-1 and HTLV-2 was found with infection rates 0.13% and 0.05% among all population samples for HTLV-1 and HTLV-2, respectively. The highest percentages of infection, 0.39% and 0.20%, were found in the high risk group, while only 0.06% and 0.03% in the blood donor group. There was only one case of HTLV-1 infection (0.11%) among patients with malignant hematological diseases. Of seven HTLV-1 positive cases, six were co-infected with HBV, two with HCV and one with HIV. Among three HTLV-2 positive individuals all were co-infected with HBV, one with HCV. Conclusions: HTLV-1 and HTLV-2 have been detected in the Central China at low prevalence, with the higher infection rate among high risk group. It was also found that co-infection of HTLV-1/2 with HIV and HBV occurred, presumably due to their similar transmission routes. HTLV-1/2 antibody screen among certain population would be important to prevent the spread of the viruses. [ABSTRACT FROM AUTHOR]

Semiconductor quantum dots have very low thermal conductivities compared with bulk materials or quantum well structures. In this paper, thermal conductivity of InAs quantum dot laser active regions was determined using two different approaches. Measured conductivity is between 0.03 and 0.05 W/(m-K) for both approaches, in reasonable agreement considering the approximations used in the measurement method. This reduced thermal conductivity of the active region in quantum dot lasers has a significant effect on the laser operating characteristics. [ABSTRACT FROM AUTHOR]

We consider a supply chain system with a risk-neutral manufacturer as the leader and a risk-averse retailer as the follower with uncertain demand. At the beginning of the game, the manufacturer makes efforts on advertising and then the retailer decides its order quantity before demand realization. The retailer's risk aversion is modeled by the Value-at-Risk (CAR) approach with the downside risk constraint. The analysis of equilibrium strategies indicates some characteristics of the game are different from those under risk-neutral assumptions. We find that the manufacturer can effectively prevent the risk-averse retailer from downsizing the order quantity through advertising. In order to explain the difference, we investigate the impacts of risk aversion on the manufacturer's advertising decision and the retailer's ordering decision. We find that the retailer with moderate degree of risk aversion orders a larger volume and receives greater advertising support from the manufacturer. Moreover, the feasible combinations of target profit and downside risk for moderate risk aversion are discussed to derive the relationship of the two parameters. In addition, we make a simple analysis of the situation with two independent retailers who have heterogeneous degrees of risk aversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • The novel Ru@V 2 O 4 nanocomposite were synthesized successfully by facile hydrothermal approach. • With the introduction of Ru, the Ru@V 2 O 4 nanocomposite exhibited enhanced catalytic performance. • The synthesized Ru@V 2 O 4 nanowires possessed superior tetra-enzyme-like activities. • A very low limit of detection of 0.788/0.139 μM was obtained for H 2 O 2 /Cys detection, respectively. • This prominent technique could be applied in water samples and human serum samples. In the last decades, nanozymes have drawn significant attention because of their higher stability and lower preparation cost than natural enzymes. In this report, the novel Ru@V 2 O 4 nanocomposite with multi-enzyme-like activities has been synthesized via one-step hydrothermal method and simple stirring. It was proved that the prepared Ru@V 2 O 4 nanowires presented magnificent tetra-enzyme-like activities, comprising oxidase-like (OD-like), peroxidase-like (POD-like), catalase-like (CAT-like) and superoxide dismutase-like (SOD-like) activity. Firstly, the kinetic investigation validated the OD and POD-mimics behaviors of Ru@V 2 O 4 nanowires, which were in conformity with the Michaelis-Menten kinetics. Then a bifunctional colorimetric sensing platform was constructed for the sensitive detection of H 2 O 2 and cysteine (Cys) on the basis of POD-like and OD-like enzyme activities of Ru@V 2 O 4 nanowires. H 2 O 2 could be detected by Ru@V 2 O 4 nanowires over a range of 1–500 μM and the response limit was 0.788 μM. Under optimal conditions, the degree of discoloration was linearly proportional to the concentration of Cys in the range of 3–50 μM with a low detect limit of 0.139 μM. Besides, Ru@V 2 O 4 nanowires can detect H 2 O 2 in water samples and Cys in serum samples. Therefore, this research significantly expands the application of the tetra-enzyme mimetic Ru@V 2 O 4 nanowires in the fields of biosensing, biocatalysis, environmental monitoring and medical diagnosis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Magnetic Fe 3 O 4 @MOF(M = Fe, Ti, Zr)@COFs were successfully fabricated. • Fe, Ti and Zr in MOF were investigated to reveal the influence on azo dye adsorption. • The Fe 3 O 4 @MOF(M = Fe, Ti, Zr)@COFs were used for adsorption of azo dyes in soft drinks with high capacities. • Adsorption mechanisms were systematically explored. Azo dyes in soft drinks present a serious risk to human health and are strictly limited in many countries. Herein, we demonstrate that covalent-organic framework (COF) can be facilely grown on magnetic metal–organic framework (MOF) to form three kinds of porous Fe 3 O 4 @MOF(M = Fe, Ti, Zr)@COFs composites for efficient azo dyes adsorption. Adsorption performances of Fe 3 O 4 @MOF(M = Fe, Ti, Zr)@COFs toward azo dyes were systemically investigated by adsorption kinetics, adsorption isotherms and adsorption thermodynamics. Under optimized conditions, the maximum adsorption capacities of both Fe 3 O 4 @MOF(Fe)@COF and Fe 3 O 4 @MOF(Zr)@COF for Congo red (CR) are 1250.02 and 625.13 mg g−1, and the Fe 3 O 4 @MOF(Ti)@COF for Chrysoidine (CYD) is 294.12 mg g−1, all which are higher than those of mostly previous reports. Furthermore, possible mechanisms of adsorption were revealed through Fourier-transform infrared spectra and X-ray photoelectron spectroscopy analysis. These Fe 3 O 4 @MOF(M = Fe, Ti, Zr)@COFs composites also present good biocompatibility, and exhibit high adsorption capacities for CR or CYD in soft drinks, which can be suggested as effective adsorbents for the azo dyes removal from soft drinks. [ABSTRACT FROM AUTHOR]

[Display omitted] In an effort to identify novel inhibitors of nuclear factor kappa B (NF-κB), twenty five pyranochalcone derivatives were synthesized and evaluated for their in vitro activities against TNF-α induced NF-κB inhibition in HEK293T cells. Among all of these derivatives, several displaying the same acrylate moiety on the B ring exhibited potent inhibition, with IC 50 values ranging from 0.29 to 10.46 μM. A functional study of the most potent of these compounds, designated 6b , revealed that it significantly suppressed the transcriptional expression of inflammatory factor IL-1β in lipopolysaccharide-induced RAW 264.7 macrophages, and also mildly inhibited CCL2, IL6 and TNF-α. In addition, compound 6b was found to inhibit IL-1β released in LPS-induced BMDM cells. This study demonstrates that the inhibitory effect of 6b on LPS-stimulated inflammatory mediator production in the mouse macrophage cell line RAW 264.7 correlates with the suppression of the NF-κB and MAPK signaling pathways. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel europium-based MOF (1) was designed and synthesized. • 1 was applied in simultaneous detection and removal of tetracycline (TC). • 1 possesses ultrasensitive recognition and high adsorption capacity toward TC. • Mechanisms of recognition and adsorption were systematically explored. • 1 was used for TC detection in real samples with satisfactory recoveries. The misuse of tetracycline (TC) will cause adverse effects on environment and has become a serious problem threatening human health. In this work, a novel bifunctional europium-based metal organic framework (1) containing characteristic metal chains was successfully synthesized via a facile one-pot hydrothermal method for the first time and used in simultaneous detection and removal of TC. Detailed characterizations including scanning electron microscope, energy dispersive X-ray spectroscope, Fourier-transform infrared, X-ray diffraction and X-ray single crystal diffraction were conducted to confirm the successful synthesis of 1. Subsequently, the prepared 1 showed significant fluorescence enhancement at 615 nm with a wide sensitive range (0.05–60 μM) and low detection limit (3 nM) for detection of TC under pH 9. The excellent adsorption behaviours (387.14 mg g−1) of 1 toward TC were demonstrated by kinetic and equilibrium experiments. Possible mechanisms of recognition and adsorption including host-guest capability of Eu nodes, hydrogen bonding, π-π interactions and electrostatic attraction were further explored. In addition, the practical feasibilities of 1 for TC sensing were further investigated in real samples with satisfactory recoveries (94.89 %−112.86 %, RSD ≤ 6.03 %). This work provides a facile strategy for design of MOF-based bifunctional turn-on fluorescence sensor for efficient TC monitoring. [ABSTRACT FROM AUTHOR]

Multiple mycotoxins may co-occurred in a single product and cause serious threats to public health. Herein, a multiplex immunochromatographic assay (mICA) was developed based on novel α-Fe 2 O 3 nanocubes (FNCs) as signal tags for the simultaneous detection of deoxynivalenol (DON) and aflatoxins B 1 (AFB 1). The FNCs with eminent water-dispersibility and stability were synthesized by a one-step hydrothermal process, which can rapidly label monoclonal antibodies (mAbs) to form FNCs-mAb probe. Under optimal experimental conditions, the visual limit of detection for DON and AFB 1 were 0.18 ng/mL and 0.01 ng/mL, respectively, which were at least 2-fold improvement compared with the traditional gold nanoparticles based mICA. Furthermore, DON and AFB 1 residual in mung bean, millet and corn were successfully detected by the proposed biosensor, and the average recovery rates were 93.3%–128.3%. Thus, this work indicated that the developed FNCs-mICA provided a sensitive, rapid and reliable on-site simultaneous detection of multiple mycotoxins. • A multiplex biosensor was constructed to sensitive detect deoxynivalenol and aflatoxins B 1. • The α-Fe 2 O 3 nanocubes with eminent water-dispersibility and stability as signal tags. • The sensor can detect deoxynivalenol and aflatoxins B 1 as low as 0.18 ng/mL and 0.01 ng/mL, separately. • The approach exhibited high selectivity and real food sample testing. [ABSTRACT FROM AUTHOR]

• The carbon selenide nanofilms modified carbon cloth (CSe 2 NF/CC) was fabricated. • CSe 2 nanofilms enhance the electrocatalytic oxidation activity of the electrode. • The CSe 2 NF/CC has been successfully used in food samples for nitrite detection. Large uptakes of nitrite have been proven to be detrimental to human health, therefore, the development of high-performance nitrite sensors is highly emergent. Herein, a carbon selenide nanofilms modified carbon fiber cloth (CSe 2 NF/CC) electrode was obtained via in-situ synthesis to detect nitrite. The electrode integrates the collective merits of macroporous CC and pleated carbon selenide nanofilms, possessing a low overpotential of 0.83 V, a high electrochemical active surface area (EASA) of 5.39 cm2, great electrical conductivity, and fast charge transport as well as ion diffusion. The proposed electrode achieved a low limit of detection of 0.04 μmol L−1 (S/N = 3), a high sensitivity of 2048.56 μA mmol L−1 cm−2, excellent selectivity, and long-term stability. Additionally, the CSe 2 NF/CC was successfully used for nitrite detection in different food samples such as pickled vegetables and sausage samples. [ABSTRACT FROM AUTHOR]

• Metal-polydopamine framework (MPF) based lateral flow assay (LFA) was developed. • MPF displayed excellent affinity with antibodies to detect tetracycline. • Assay performance of this LFA was 66-fold higher than that of traditional AuNP-LFA. • This work expands the application of MOFs as a novel label in immunoassays. Gold nanoparticles (AuNPs)-based lateral flow assay (LFA) enables a rapid detection of tetracycline (TET) in food samples but suffers from low sensitivity. Herein, metal-polydopamine framework (MPF), as a label, was employed to load monoclonal antibodies (mAbs) directly as the probe in LFA for highly sensitive sensing of TET. Combining zeolitic imidazolate framework (ZIF-67) and polydopamine (PDA), a stable MPF with large size, well water-dispersible, excellent affinity and optical properties was prepared through a versatile layer-by-layer assembly (LLA) strategy. Under optimized conditions, the biosensor (MPF-LFA) exhibited a great linear relationship in the range of 0.09–6 ng/mL and a detection limit of 0.045 ng/mL for TET detection, which was over 66-fold more sensitive than traditional AuNPs based LFA. Furthermore, the MPF-LFA was successfully applied to the screening of TET in fish, chicken, milk and shrimp samples with satisfied recoveries from 91% to 114%. [ABSTRACT FROM AUTHOR]

P -nitrophenol (PNP) has been widely applied to industry processing for many purposes, but the persistence and toxicity of residuum may pose risks to human health. To analyze PNP in industrial and agricultural wastewater, a versatile fluorescent probe sensing platform was proposed. In this work, we devised a fluorescence approach that utilized nitrogen, silicon co-doped carbon dots (N,Si-CDs) to monitor PNP originating from the inner filter effect (IFE). The N,Si-CDs were generated in a one-step hydrothermal synthesis, and which possessed outstanding fluorescence signal and water-dispersity. Emission at 441 nm was monitored with excitation at 360 nm using a common spectrofluorometer. The method achieved an exceptionally low limit of detection (LOD) of 0.011 μM. Furthermore, this method not only eliminates the interference from metal ions and acid ions, but also provides a potential application prospect for N,Si-CDs in the field of water monitoring. Analysis of tap and lake water led to 93.30–106.30% recoveries and <1% relative standard deviation at 2.5–25 μM PNP concentrations. Unlabelled Image • A novel fluorescence nanoprobe based on N,Si-CDs was designed for PNP detection. • The N,Si-CDs possessed outstanding fluorescence signal and water-dispersity. • This fluorometric assay has lower detection limit than other detection methods. • This fluorescence nanoprobe had been used to detect PNP in actual water samples with great recoveries. [ABSTRACT FROM AUTHOR]

• The rhombic-like Al nanosupporter (RAlNS) based fluorescence immunochromatographic assay was constructed. • The synthesized RAlNS can label antibodies in one-step stirring, avoiding the use of the complex cross-linkers. • The sensor possessed high sensitivity and specificity for tetracycline (TET). • Significant recovery rates of TET detection in real samples demonstrates the sensor's applicability. Fluorescence-based lateral flow immunoassay (FLFIA) is a prospective technology in detecting tetracycline (TET). However, the existing fluorescent materials (FMs) often require cross-linkers to bind with antibodies (Abs) to form FLFIA FM-Ab probe, which complicates the modification process and may affect the fluorescence intensity of FMs. Herein, the rhombic-like Al nanosupporter (RAlNS) was prepared via a one-step hydrothermal method and used for designing fluorescence nanosupporter for FLFIA to detect TET in real samples. The RAlNS not only possessed excellent water stability, strong fluorescence intensity and favorable thermal stability, but also could adsorb Abs to obtain FMs-Ab probe by simple centrifugation. Under optimal conditions, the limit of detection (LOD) of RAlNS-FLFIA was 0.0516 ng/mL (n = 3), which was 18 times lower than traditional colloidal gold-based LFIA. Meanwhile, the proposed sensor also exhibited high specificity for TET against other antibiotics. Furthermore, the RAlNS-FLFIA was successfully applied to the detection of TET in beef, chicken, milk and honey samples, separately, which demonstrated a significant recovery of 80.40–112.05%. The novel RAlNS-FLFIA provided great potential for the detection of various analytes in food analysis. [ABSTRACT FROM AUTHOR]

In this work, to prevent the spoilage of food by microbial contamination, copper sulfide nanoparticles (CuS NPs) with photothermal effect were successfully synthesized by a one-step hydrothermal method and uniformly dispersed in natural carrageenan (Carr) to obtain Carr/CuS films. Photothermal-induced antibacterial testing confirmed that the Carr/CuS film has a broad-spectrum antibacterial activity against Escherichia coli (99.2%) and Staphylococcus aureus (99.9%). Antibacterial test on beef also proved that near-infrared (NIR) irradiation significantly improved the antibacterial ability of the Carr/CuS film against bacteria on the food sample. In addition, compared with the Carr film, the Carr/CuS film with high transparency showed enhanced mechanical properties and thermal stability. The introduction of this NIR-induced strategy is expected to open a new way for broadening the application of antibacterial packaging. Image 1 • The Carr/CuS nanocomposite film exhibits controllable photothermal conversion effect. • The Carr/CuS photothermal film displays superior antibacterial activity against E. coli and S. aureus. • The antibacterial treatment time of this photothermal film decreased to 10 min under the 808 nm near-infrared irradiation. • The Carr/CuS nanocomposite film is almost colorless and highly transparent. • The addition of CuS NPs enhances the mechanical properties and thermal stability of carrageenan-based films. [ABSTRACT FROM AUTHOR]

• A label-free and dual-readout biosensor was constructed to detect E. coli O157:H7. • The Fe 3 O 4 @CuS could capture targets directly and possessed PTEs to amplify signals. • An ideal analytical performance with high sensitivity and specificity was achieved. • The sensor were successfully used in food samples for E. coli O157:H7 detection. Herein, a label-free and dual-readout immunochromatographic test strip (ITS) for the sensitive detection of Escherichia coli (E. coli) O157:H7 by taking advantages of the strong capture ability of Fe 3 O 4 @CuS nanostructures (NSs) towards bacteria and their ultrahigh photothermal effects (PTEs) was reported. Especially, without the customarily antibody (Ab)-labeled probe, Fe 3 O 4 @CuS NSs could be adsorbed onto the surfaces of bacteria to form Fe 3 O 4 @CuS-bacteria conjugates and then trapped by immobilized Abs on the test line (T-line), forming a characteristic yellow band. After direct immunoreactions, the PTEs of Fe 3 O 4 @CuS NSs endowed T-line to be irradiated by an 808 nm infrared light, obtaining satisfactory sensitivity and accuracy. Under optimal conditions, E. coli O157:H7, as low as 103 and 102 CFU/mL, could be monitored in colorimetric and photothermal modes. Additionally, E. coli O157:H7 was successfully detected in beef, chicken, milk and honey samples by this proposed platform with a recovery of 80–120%. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) have attracted tremendous interest due to their promising applications, including electrocatalysis originating from their unique structural features. However, it remains a challenge to prepare COFs for p-nitrophenol (PNP) and o-nitrophenol (ONP) electrocatalysis because it is quite difficult to manipulate their dimension, composition, and morphology with abundant active sites. Here, a facile ambient temperature synthesis of unique Fe 3 O 4 -based magnetic COFs nanosphere (Fe 3 O 4 @AT-COFs) with different surface morphologic structure is reported, which exhibits higher surface area, good water dispersity, long-term stability, excellent electrical conductivity and pre-concentration effect. The prepared Fe 3 O 4 @AT-COF-based electrochemical sensor is then directly employed for the simultaneous detection of PNP and ONP with a wide linear detection range of 10–3000 μM and low detection limits (LOD) of 0.2361 μM and 0.6568 μM, respectively. Meanwhile, the Fe 3 O 4 @AT-COF can be also well-applied in lake and tap water for monitoring PNP and ONP with outstanding sensitivity and reliability, which is expect to be a high-efficient electrocatalyst with great promise for signal amplification of electrochemical sensing. Image 1 • Facile synthesis of Fe 3 O 4 -based magnetic COFs with different surface morphologic structure. • COFs as the enrichment carriers of Fe 3 O 4 were employed for amplifying electrochemical sensing signals. • Fe 3 O 4 plays a dual role in magnetic attraction with the electrode and synergistic catalysis effect with COFs. • A sensitive and reliable simultaneously detection of PNP and ONP were achieved with a low limit of detection. [ABSTRACT FROM AUTHOR]

• Ferrous selenide nanorods on carbon cloth was prepared via in situ synthesis. • The self-supported nitrite sensor displays high sensitivity and low detection limit. • The proposed sensor detected nitrite in real samples with acceptable results. In this paper, a self-supported electrode for nitrite detection was obtained by loading ferrous selenide nanorods on carbon cloth (FeSe NR/CC) via in situ synthesis. The morphology and chemical composition of the FeSe NR/CC were characterized using scanning electron microscope (SEM), X-ray diffractogram (XRD), and X-ray photoelectron spectroscopy (XPS). Owing to the synergistic effect between FeSe nanorods and carbon cloth, the rich redox active sites, and the lower transferring resistance, the binder-free and self-supported sensor based on FeSe NR/CC exhibits a wide linear relationship from 0.625 μM to 6775.5 μM, a fast-current response of 3 s, and a high sensitivity of 1107.7 μA mM−1 cm−2. The detection limit of the FeSe NR/CC was evaluated as 0.07 μM and the developed sensor displays excellent selectivity, stability, and reproducibility. Additionally, the as-prepared sensor has been successfully applied to detect nitrite in pickled vegetable samples, proving its feasibility for practical applications. Therefore, the self-supported and binder-free electrode proposed in this study could be used as a highly efficient and cost-effective electrochemical nitrite sensing device to achieve rapid quantitative detection of nitrite in food samples. [ABSTRACT FROM AUTHOR]

• Gallic acid serves as a green reducing agent to synthesize silver nanoparticles. • The photothermal conversion efficiency of GA-Ag NPs is as high as 48.7%. • GA-Ag NPs integrate photothermal effect with inherent antibacterial property. • GA-Ag NP hydrogel exhibits excellent broad-spectrum sterilization property. • Wound healing tests in vivo confirm the antibacterial effect and biocompatibility. Because of the indiscriminate use of antibiotics and threats of the drug resistance, bacterial wound infection remains one of the most difficult medical issues. Therefore, it is of great significance to develop novel antibacterial platforms. In this work, we successfully prepared gallic acid functional silver nanoparticles (GA-Ag NPs) by a one-pot method and then embedded them into the network structure of a biocompatible polysaccharide to obtain a novel hydrogel (GA-Ag NP hydrogel) with outstanding bactericidal effect. In this system, the embedded GA-Ag NPs not only act as an antibacterial agent sustainably released from the matrix of the hydrogel to realize sterilization, but also act as a photothermal agent that effectively and controllably converts 808 nm near-infrared ray light into heat to kill bacteria. In vitro testing verified the outstanding broad-spectrum sterilization property of the GA-Ag NP hydrogel against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). In vivo wound healing experiments confirmed the practical potential of this hydrogel in combating bacterial infections and accelerating wound healing. Hemolysis and cytotoxicity experiments showed that it has good biocompatibility. The development of this novel antibacterial hydrogel opens a new way to strengthen the antimicrobial arsenal for fighting bacterial infections. [ABSTRACT FROM AUTHOR]

Silicon-doped carbon quantum dots (Si-CQDs) were employed to fabricate a ratiometric fluorometric probe that shows high selectivity for hydroquinone (HQ). The Si-CQDs were prepared through hydrothermal treatment of N-[3-(trimethoxysilyl)propyl]-ethylenediamine. If HQ is oxidized in a solution of the Si-CQDs, 1,4-benzoquinone will be formed which quenches the blue fluorescence (with excitation/emission peaks at 360/435 nm) of the Si-CQDs. Simultaneously, intense green fluorescence (with a emission peak at 513 nm) appears, probably due to the formation of n-π clathrates or of a quinone imine between 1,4-benzoquinone and amino groups on the surface of the Si-CQDs. The ratio of the green and blue fluorescence can be applied to the determination of HQ with a 0.077 μM detection limit. The analytical range extends from 1 to 40 μM. [ABSTRACT FROM AUTHOR]