Integration of a photoelectrochemical cell in a flow system for quantification of 4-aminophenol with titanium dioxide

ZnSe nanodisks:Ti3C2 MXenes-modified electrode for nucleic acid liquid biopsy with photoelectrochemical strategy

ZnSe nanodisks:Ti₃C₂ MXene complex was prepared for the first time. Based on its remarkable photoelectrochemical performance, combined with the enzyme-free toehold-mediated strand displacement reaction, a photoelectrochemical biosensor for the detection of the non-small-cell cancer biomarker ctDNA KRAS G12D was developed. ZnSe nanodisks were in situ grown on Ti₃C₂ MXene surface by two-step hydrothermal method. The high conductivity and adjustable band gap of MXene significantly enhanced the photoelectric response of ZnSe. Subsequently, the photoelectrochemical biosensor was prepared by combining with the signal amplification function of p-aminophenol and the enzyme-free toehold-mediated strand displacement reaction on the modified ITO electrode surface. Under the optimized conditions, the linear detection range is 0.5 ~ 100.0 fM, and the detection limit is 0.2 fM, which realizes the sensitive detection of KRAS G12D. The photoelectrochemical biosensor constructed opens up a new pathway for the preparation of new Mxene-based composite materials and the research of photoelectrochemical biosensor. Nucleic acid liquid biopsy with ZnSe nanodisks:Ti₃C₂ MXene photoelectroactive modified electrode.

Physical properties of PVDF-GO/black-TiO2 nanofibers and its photocatalytic degradation of methylene blue and malachite green dyes

Black TiO2 and graphene oxide (GO) have attracted intensive attention as an effective catalyst on visible light driven for photodegrading of dyes. In this study, nano-black TiO2 was prepared by a simple hydrogenation of the anatase titanium oxide, and the graphene oxide was prepared by applying the modified Hummers method. The diffuse reflectance spectroscopy has been investigated to find out the optical energy gaps of the treated and nano-black samples. The prepared powders and nanofiber membranes are carefully examined to ensure their single phase and compound structure formation as well as to measure the equivalent crystallite size and particle distributions. The optimum degradation efficiency of malachite green and methylene blue dyes occurred at pH values of 8 and 10, respectively. The maximum photocatalytic degradation efficiencies of malachite green (MG) and methylene blue (MB) were found to be 74 and 39%, respectively, under visible light after 30 min. The degradation efficiency of MG is peaked at pH 8 and 20 mg of the nano-black TiO2. The stability and flexibility of the nanofibers allow their application in a continuous system and can be reused after several cycles.