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Photocatalytic degradation of dye contaminants using nanocomposite adsorbents has emerged as a promising solution for wastewater treatment. Owing to its abundant availability, eco-friendly composition, biocompatibility, and strong adsorption activity, spent tea leaf (STL) powder has been extensively explored as a viable dye-adsorbent material. In this work, we report spectacular enhancement in the dye-degradation properties of STL powder on incorporation of ZnIn 2 S 4 (ZIS). The STL/ZIS composite was synthesized using a novel, benign, and scalable aqueous chemical solution method. Comparative degradation and reaction kinetics studies were performed onto an anionic dye, Congo red (CR), and two cationic dyes, Methylene blue (MB) and Crystal violet (CV). The degradation efficiencies of CR, MB, and CV dyes were obtained to be 77.18, 91.29, and 85.36%, respectively, using the STL/ZIS (30%) composite sample after the 120 min experiment. The spectacular improvement in the degradation efficiency of the composite was attributed to its slower charge transfer resistance (as concluded by the EIS study) and optimized surface charge (as concluded by ζ potential study). Scavenger tests and reusability tests deciphered the active species ( • O 2 - ) and reusability of the composite samples, respectively. To the best of our knowledge, this is the first report to demonstrate improvement in the degradation efficiency of STL powder on ZIS incorporation., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

A g-C 3 N 4 /ZnO (graphitic carbon nitride/zinc oxide) nanocomposite-decorated gold electrode was employed to design an antigen-antibody-based electrochemical biosensor to detect Helicobacter pylori specific toxin, vacuolating cytotoxin A (VacA). The thermal condensation method was used to synthesize the g-C 3 N 4 /ZnO nanocomposite, and the nanocomposite was deposited electrochemically on a gold electrode. The morphology as well as the structure of the synthesized nanocomposite were confirmed by scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction, and Fourier transform infrared techniques. The nanocomposite efficiently increased the sensor performance by amplifying the signals. EDC-NHS chemistry was exploited for attachment of VacA antibodies covalently with the g-C 3 N 4 /ZnO-modified gold electrode. This modified electrode was exploited for immunosensing of H. pylori -specific VacA antigen. The immunosensor was stable for up to 30 days and exhibited good sensitivity of 0.3 μA -1 ng mL -1 in a linear detection range of 0.1 to 12.8 ng mL -1 . Apart from this, the fabricated sensor showed unprecedented reproducibility and remarkable selectivity toward the H. pylori toxin VacA. Thus, the highly sensitive immunosensor is a desirable platform for H. pylori detection in practical applications and clinical diagnosis., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

In this paper, we report the synthesis of zinc indium sulfide (ZnIn 2 S 4 ) microspheres synthesized via a low-temperature route, and the as-synthesized material was used for photocatalytic degradation of malachite green (MG), methyl orange (MO), and Direct Red 80 (DR-80) dyes. The as-synthesized material was characterized by powder X-ray diffraction and field-emission scanning electron microscopy for studying the crystal structure and surface morphology, respectively. Fourier transform infrared spectroscopy was performed to determine the functional groups attached. UV-Visible absorption spectrometry was done for light absorbance and band gap analysis, and Mott-Schottky analysis was performed to determine the nature and flat band potential of the material. A scavenger study was performed to analyze the active species taking part in the degradation process. The reusability of the material was tested up to four cycles to check the reduction in efficiency after each cycle. A time-correlated single-photon counting study was performed to observe the average lifetime of generated excitons during photocatalysis. It was found that the as-synthesized porous sample is more efficient in degrading the cationic dye than anionic dyes, which is further explained in the article., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

The present report employed nanobroom (NB)-shaped two-dimensional molybdenum diselenide (MoSe 2 ) for the preparation of a sensing matrix for the detection of Salmonella paratyphi . An aptamer specific to salmonella was immobilized onto MoSe 2 NB-modified fluorine-doped tin oxide via glutaraldehyde cross-linking. Structural and morphological characterizations were performed using UV-vis spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction techniques. Characterizations confirmed the nanobroom morphology and nanosize of the MoSe 2 material. Electrochemical studies revealed a good linear detection range of 10 -2 -10 -10 CFU/mL with low detection limit of 1 × 10 -10 CFU/mL and with R 2 = 0.98. The developed preferable nanobroom-shaped sensing matrix can provide a promising platform for rapid and accurate detection of Salmonella in real samples due to its tremendous stability and sensitivity., Competing Interests: The authors declare no competing financial interest.