Search

The continuous emergence of food additives and contaminants in edibles, especially confectioneries, demands advanced detection methods to ensure public health and safety. Vanillin (VAL) and sulfadiazine (SD) are of paramount concern due to their extensive application in various products. While VAL is favored for its flavoring attributes, SD, a common antibiotic, can inadvertently contaminate food items. For accurate and swift detection of these compounds, we introduced an innovative electrochemical sensor using cobalt oxide nanostructures. Notably, synthesizing these nanostructures through a green approach using glucose and starch is a significant advancement, offering both environmental benefits and enhanced material properties. The novelty of the material lies in its eco-friendly synthesis route and superior electrocatalytic performance. Preliminary results indicate a promising limit of detection (LOD) VAL= 0.003 µM & SD= 0.0055 µM and a broad linear range 0.02–209 µM emphasizing its potential for real-world food quality monitoring. This work, therefore, provides a crucial intersection of sustainable material synthesis and effective food contaminant detection, heralding a new era in food safety evaluation.

In recent years, there has been a significant interest in the advancement of electrochemical sensing platforms to detect antipyretic drugs with high sensitivity and selectivity. The electrochemical determination of acetaminophen (PCT) was studied with strontium molybdate with a functionalized carbon nanotube (SrMoO4@f-CNF) nanocomposite. The SrMoO4@f-CNF nanocomposite was produced by a facial hydrothermal followed by sonochemical treatment, resulting in a significant enhancement in the PCT determination. The sonochemical process was applied to incorporate SrMoO4 nanoparticles over f-CNF, enabling a network-like structure. Moreover, the produced SrMoO4@f-CNF composite structural, morphological, and spectroscopic properties were confirmed with XRD, TEM, and XPS characterizations. The synergistic effect between SrMoO4 and f-CNF contributes to the lowering of the charge transfer resistance (Rct=85 Ω·cm2), a redox potential of Epc=0.15 V and Epa=0.30 V (vs. Ag/AgCl), and a significant limit of detection (1.2 nM) with a wide response range of 0.01–28.48 µM towards the PCT determination. The proposed SrMoO4@f-CNF sensor was studied with differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques and demonstrated remarkable electrochemical properties with a good recovery range in real-sample analysis.

In this work, a nickel tungstate nanospheres-anchored polyaniline nanocomposite (NiWO4/PANI) was prepared by using a hydrothermal route followed by a chemical oxidative polymerization route and explored as an electrode material for the determination of theobromine (TB). The X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis confirm the structural-compositional details of NiWO4/PANI nanocomposite. Further, the successful fabrication of NiWO4 nanospheres perfectly anchoring on the conductive matrix of PANI is revealed by transmission electron microscope (TEM) analysis. The N2 adsorption-desorption isotherm analysis revealed the specific surface area of the composite is 28.49 m2/g. Due to the feasible multiple electroactive sites and the synergistic effect between NiWO4 and conductive PANI matrix in the NiWO4/PANI nanocomposite, it enables rapid electron migration and possesses high electrical conductivity during the sensing performances. From the amperometric i-t method, NiWO4/PANI sensor exhibits a wide linear range (0.05–1350.6 μM) and a low detection limit (0.0079 µM). Besides, NiWO4/PANI based sensor shows excellent stability, anti-interference ability and reproducibility, suggesting NiWO4/PANI composite-modified sensors could be a potential candidate for determining TB in food samples with suitable recovery ranges.

This work presents the detection of hypoxanthine (HXA), a purine derivative that is similar to nucleic acids who overconsumption can cause health issues, by using hydrothermally synthesized cerium phosphate (CePO4) followed by a sonochemical approach for CePO4 decorated with a functionalized carbon nanofiber (CePO4@f-CNF) nanocomposite. The formation of the nanocomposite was confirmed with X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). A CePO4@f-CNF nanocomposite is used to modify a glassy carbon electrode (GCE) to analyze the electrochemical detection of HXA. Cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS), and Differential pulse voltammetry (DPV) were used to examine the electrochemical properties of the composite. As a result, the modified electrode exhibits a larger active surface area (A = 1.39 cm2), a low limit of detection (LOD) at 0.23 µM, a wide linear range (2.05–629 µM), and significant sensitivity. Therefore, the CePO4@f-CNF nanocomposite was used to study the real-time detection in chicken and fish samples, and it depicted significant results.

Dimetridazole (DMZ), a nitroimidazole derivative, is a notable antibiotic that has garnered growing interest in the medical community owing to its noteworthy pharmacological and toxicological properties. Increasing interest is being directed toward developing high-performance sensors for continuous monitoring of DMZ in food samples. This research investigated an electrochemical sensor-based nano-sized ErVO4 attached to a sheet-like g-CN-coated glassy carbon electrode to determine dimetridazole (DMZ). The chemical structure and morphological characterization of synthesized ErVO4@g-CN were analyzed with XRD, FTIR, TEM, and EDS. Irregular shapes of ErVO4 nanoparticles are approximately 15 nm. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were followed to examine the electrochemical performance in pH 7 phosphate buffer solution for higher performance. This electrochemical sensor showed a low detection limit (LOD) of 1 nM over a wide linear range of 0.5 to 863.5 µM. Also, selectivity, stability, repeatability, and reproducibility studies were investigated. Furthermore, this electrochemical sensor was applied to real-time milk sample analysis for the detection of analytes.

This work reports the effect of a MAPbBr3 layer in CsPbBr3 perovskite light-emitting diodes (PeLEDs). The MAPbBr3 layer employed MAPbBr3 powder as the evaporation source, which was obtained from using MAPbBr3 bulk crystals prepared by the inverse temperature crystallization method. The devices exhibited the best quality and performance when a 20-nm-thick MAPbBr3 layer was used as the nucleation and hole transport layer. The rc-MAPbBr3/CsPbBr3 structure apparently boosted the carrier lifetime such that the injection holes and electrons quickly recombine and then transfer into photons and emissions. The champion luminescence and external quantum efficiency were 21,850 cd/m2 at a bias of 7.0 V and 1.18% at a bias of 6.5 V, respectively.

Electrochemical sensors have become a pivotal tool in ensuring the safety and security of the global food supply chain, which is crucial for public health, economic stability, and environmental sustainability. Modern food systems, with their complex global distribution and varied processing methods, require advanced solutions for detecting contaminants and maintaining food quality. This review delves into recent advancements in electrochemical food sensor technology, highlighting their operating principles, types, cutting-edge materials, and methods enhancing their effectiveness. These sensors are adept at identifying a broad range of foodborne pathogens, chemical contaminants, and adulterants while monitoring food freshness and quality. Innovations include using nanomaterials and conductive polymers and shifting towards miniaturized, portable devices for on-site and real-time analysis. The review also addresses challenges such as sensitivity, selectivity, and matrix effects, pointing out emerging trends and future research avenues to overcome these hurdles. Regulatory and standardization issues relevant to adopting these technologies in food safety protocols are also considered. Highlighting the last three years, this review emphasizes the indispensable role of electrochemical sensors in boosting food safety and security and the need for ongoing innovation and cross-disciplinary cooperation to advance this area.

Cardiovascular diseases (CVDs) represent a significant challenge in global health, demanding advancements in diagnostic modalities. This review delineates the progressive and restrictive facets of nanomaterial-based biosensors in the context of detecting N-terminal pro-B-type natriuretic peptide (NT-proBNP), an indispensable biomarker for CVD prognosis. It scrutinizes the escalation in diagnostic sensitivity and specificity attributable to the incorporation of novel nanomaterials such as graphene derivatives, quantum dots, and metallic nanoparticles, and how these enhancements contribute to reducing detection thresholds and augmenting diagnostic fidelity in heart failure (HF). Despite these technological strides, the review articulates pivotal challenges impeding the clinical translation of these biosensors, including the attainment of clinical-grade sensitivity, the substantial costs associated with synthesizing and functionalizing nanomaterials, and their pragmatic deployment across varied healthcare settings. The necessity for intensified research into the synthesis and functionalization of nanomaterials, strategies to economize production, and amelioration of biosensor durability and ease of use is accentuated. Regulatory hurdles in clinical integration are also contemplated. In summation, the review accentuates the transformative potential of nanomaterial-based biosensors in HF diagnostics and emphasizes critical avenues of research requisite to surmount current impediments and harness the full spectrum of these avant-garde diagnostic instruments.

Pharmaceuticals are generally designed to be nondegradable or slowly degradable to prevent chemical degradation as it is employed as therapeutics for human or animal. This results in a widespread risk when they enter, accumulate or persist in the environment. Pharmaceutical pollution is emerging as wide-reaching concern due to its ostensible consequences, by dissemination in the environment. This demands for inventing novel analytical routes to monitor and mitigate pharmaceutical pollutants. Therefore, this paper presents synthesis of Zinc molybdate nano particles embedded on functionalized carbon nanofibers to fabricate glassy carbon electrode towards sensitive detection of Sulfadiazine (SDZ). The synergistic effect produced in the composite had enabled it with improved charge transfer kinetics and benefited with more active surface area. The proposed ZnMoO4/f-CNF sensor shows significant static characteristics such as wide linear response ranges (0.125 to1575.2 μM), low detection limit (0.0006 μM) and selectivity, and increased stability. Also, its practicability was analyzed by SDZ detection in real samples.

Abstract Among many transition-metal oxides, Fe3O4 anode based lithium ion batteries (LIBs) have been well-investigated because of their high energy and high capacity. Iron is known for elemental abundance and is relatively environmentally friendly as well contains with low toxicity. However, LIBs based on Fe3O4 suffer from particle aggregation during charge–discharge processes that affects the cycling performance. This study conjectures that iron agglomeration and material performance could be affected by dopant choice, and improvements are sought with Fe3O4 nanoparticles doped with 0.2% Ti. The electrochemical measurements show a stable specific capacity of 450 mAh g−1 at 0.1 C rate for at least 100 cycles in Ti doped Fe3O4. The stability in discharge capacity for Ti doped Fe3O4 is achieved, arising from good electronic conductivity and stability in microstructure and crystal structure, which has been further confirmed by density functional theory (DFT) calculation. Detailed distribution function of relaxation times (DFRTs) analyses based on the impedance spectra reveal two different types of Li ion transport phenomena, which are closely related with the electron density difference near the two Fe-sites. Detailed analyses on EIS measurements using DFRTs for Ti doped Fe3O4 indicate that improvement in interfacial charge transfer processes between electrode and Li metal along with an intermediate lithiated phase helps to enhance the electrochemical performance.

The extensive use of antibiotics has rapidly spread antibiotic resistance, which poses significant health risks to humans. Unfortunately, despite this pressing issue, there is still a lack of a reliable on-site detection method for the residues of antibiotics, such as nilutamide (Nlu). Consequently, there is an urgent need to develop and perfect such a detection method to effectively monitor and control antibiotic residues. In this study, the hydrothermal development of copper-metal-organic framework (Cu-MOF) polyhedrons on the functionalized carbon nanofiber (f-CNF) matrix allowed for the detection of Nlu in biological liquids via a sensitive amperometry technique. Further electrochemical detection of Nlu took place with the cyclic voltammetry (CV) technique Cu-MOF/f-CNF. Analytical and spectroscopic approaches were used to confirm the successful synthesis of Cu-MOF/f-CNF. The prepared material was decorated on the surface of GCE and performed as an electrochemical Nlu sensor, with a broad linear range of 0.01 to 141.4 μM and 2 nM as a lower limit of detection. In addition, the composites had a large surface area and many dedicated sites, which improved electrocatalysis. In practical applications, Cu-MOF/f-CNF/GCE provides a novel strategy for improving electrochemical activity by measuring Nlu concentrations in biological samples.

Abstract This work describes the effect of a rubidium chloride (RbCl) interlayer in CsPbBr3 perovskite light-emitting diode (LED) structures. RbCl crystallites exhibited polyhedral structures and lattice parameters similar to those of CsPbBr3 perovskite crystallites. The lattice mismatch between the RbCl interlayer and CsPbBr3 active layer was only approximately 2%. The devices exhibited the best quality and performance when RbCl was used as the nucleation and carrier confinement layer. The crystallite sizes of CsPbBr3 with 0.2-, 0.5-, and 1-nm-thick RbCl bottom layers were 55.1, 65.4, and 55.1 nm, respectively. The full width at half maximum (FWHM) of the photoluminescence (PL) emission peak for CsPbBr3 with the RbCl bottom layer was 0.096 eV.

Reactive oxygen and nitrogen species (RONS), including 3-nitro-l-tyrosine, play a dual role in human health, inducing oxidative damage and regulating cellular functions. Early and accurate detection of such molecules, such as L-tyrosine in urine, can serve as critical biomarkers for various cancers. In this study, we aimed to enhance the electrochemical detection of these molecules through the synthesis of La2Sn2O7/f-HNT nanocomposites via a simple hydrothermal method. Detailed structural and morphological characterizations confirmed successful synthesis, consistent with our expected outcomes. The synthesized nanocomposites were utilized as nanocatalysts in electrochemical sensors, showing a notable limit of the detection of 0.012 µM for the real-time detection of 3-nitro-l-tyrosine. These findings underscore the potential of nanomaterial-based sensors in advancing early disease detection with high sensitivity, furthering our understanding of cellular oxidative processes.

Ultrasonic-enhanced surface-active bismuth trisulfide based core–shell nanomaterials were developed and used as an efficient modified electrode material to construct a highly sensitive antibiotic sensor. The core–shell Bi2S3@GCN electrode material was directly synthesized by in-situ growth of GCN on Bi2S3 to form core–shell like nanostar (Ti-horn, 30 kHz, and 70 W/cm2). The electrocatalyst of Bi2S3@GCN nanocomposites was efficaciously broadened towards electrochemical applications. As synthesized Bi2S3@GCN promoted the catalytic ability and electrons of GCN to transfer to Bi2S3. The single-crystalline GCN layers were uniformly grown on the surface of the Bi2S3 nanostars. Under the optimal conditions of electrochemical analysis, the CPL sensor exhibited responses directly proportional to concentrations (toxic chemical) over a range of 0.02–374.4 μM, with a nanomolar detection limit of 1.2 nM (signal-to-noise ratio S/N = 3). In addition, the modified sensor has exhibited outstanding selectivity under high concentrations of interfering chemicals and biomolecules. The satisfactory CPL recoveries in milk product illustrated the credible real-time application of the proposed Bi2S3@GCN sensors for real samples, indicating promising potential in food safety department and control. Additionally, the proposed electrochemical antibiotic sensor exhibited outstanding performance of anti-interfering ability, high stability and reproducibility.

Harmful chemicals are always found in the environment and it is necessary to construct a viable sensor to detect those chemicals. In order to construct an electrochemical sensing platform, designing an electrode using bismuth mixed oxides are more important and which grabbed more attention due to its high electrocatalytic ability and conductivity. In this literature, we report a facile synthesis of thorn apple like structured pure bismuth molybdate (Bi2MoO6) using a simple hydrothermal assisted one-step calcination method and we report a facile method to sense 4-cyanophenol by electrochemical technique. Bi2MoO6 modified (Glassy Carbon electrode) GCE possess two linear ranges 0.1–39.1 µM and 46.6–110.1 µM with excellent detection limit 0.008297 µM and 0.01097 µM. Also, this novel sensor is steady with good stability, repeatability, and reproducibility. Successfully, the environmental water sample is analyzed as a real sample with a feasible and quantification results which were compared with HPLC analysis.

Monodispersed magnetite nanoparticles were obtained by investigating the different synthesis parameters of the solvothermal method. The morphology and chemical structure of the Fe3O4 nanoparticles were characterized by Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission electron microscope (TEM), Dynamic Light Scattering (DLS) and Vibrating sample magnetometer (VSM). Results indicated that without the addition of water, it forms the minor phase of iron instead of magnetite. Furthermore, the size of nanoparticles is tunable in the range of 117.7 to 217.6 nm by changing the amounts of water, PSSMA and NaOH. The amount of PSSMA restricts the growth of the nanoparticles and narrow the size distribution and a hydrophilic surface was obtained. Synthesized magnetite nanoparticles were successfully conjugated with carbon dots. The resulting nanoparticles exhibited good fluorescence characteristics. Cytotoxicity tests confirmed that nanoparticles are non-toxic. Both magnetite and C-dots/Fe3O4 nanoparticles are good potential candidates for biomedical applications specifically for bioimaging and biosensing in the future.

The chemical sensing for the trace level detection of silver ion in aqueous solution still remains a challenge using simple, rapid, and inexpensive method. We report that thionine can be used as a fluorescent probe for the detection of Ag+ ion. The successive addition of Ag+ ion to the solution containing thionine quenches (turns-off) the fluorescence intensity of thionine. Association and quenching constants have been estimated by the Benesi–Hildebrand method and Stern–Volmer plot, respectively. From the plot, the nature of the fluorescence quenching was confirmed as static quenching. An important feature of our chemosensor is high selectivity towards the determination of silver ion in aqueous solution over the other competitive metal ions. The detection limit of the sensor achieved 5 fM for Ag+ ion, which is superior to all previously reported chemosensors. The NMR and FT-IR studies were also carried out to support the complex formation between thionine and Ag+ ion. The practicality of the proposed chemosensor for determination of Ag+ ion was carried in untreated water samples. Keywords: Silver ions, Fluorescence, Chemosensor, Selectivity, Static quenching

In this study, BaTiO3–(Bi0.5Na0.5)TiO3 ceramics with various amounts of Ta2O5 dopant were investigated for their ability to enhance high-temperature stability to meet X9R specifications. The results were compared to those for ceramics with the common Nb2O5 additive. The best composition appeared to be 0.9BaTiO3–0.1(Bi0.5Na0.5)TiO3 with 2 mol% Ta2O5 dopant sintered at 1215 °C, which had a dielectric constant of 1386, a tanδ value of 1.8%, temperature coefficients of capacitance (TCCs) of −1.3% and 1.2%, and electrical resistivities of 2.8 × 1012 and 1.5 × 1010 Ω·cm at 25 °C and 200 °C, respectively. Its microstructure consisted of fine equiaxed grains with a perovskite structure and an average grain size of 0.46 μm and some rod-like grains of second-phase Ba6Ti17O40 with a size of approximately 3.2 μm. The Ta2O5 dopant caused a reduction in the grain size and a slight increase in trapped pores. The temperature dependence of the dielectric constant flattened and the Curie point was dramatically suppressed with the addition of Ta2O5 dopant, leading to smooth dielectric temperature characteristics over a relatively broad temperature range. The X9R formulations and their dielectric properties were highly repeatable in this study.

Mo films prepared under a single deposition condition seldom simultaneously obtain a low resistivity and a good adhesion necessary for use in solar cells. In order to surmount the obstacle, bilayer Mo films using DC sputtering at a higher working pressure and a lower working pressure have been attempted as reported in the literature. In this study, RF sputtering with different powers in conjunction with different working pressures was explored to prepare bilayer Mo film. The first bottom layer was grown at a RF sputtering power of 30 W and a working pressure of 12 mTorr, and the second top layer was deposited at 100 W and 4.5 mTorr. The films revealed a columnar growth with a preferred orientation along the (110) plane. The bilayer Mo films reported an electrical resistivity of 6.35 × 10−5 Ω-cm and passed the Scotch tape test for adhesion to the soda-lime glass substrate, thereby qualifying the bilayer Mo films for use as back metal contacts for CIGS substrates.