Interface Construction And Application Of Paper-Based Photoelectrochemical Biosensor Based On Wide-Spectrum-Responsive Materials

In recent years,the combination of bioanalysis and photoelectrochemistry（PEC）for photoelectrochemical biosensing has opens a new avenue for the sensitive and rapid detection of biomarkers and the research of biological processes.With the increasing requirements for bioanalytical sensing,the construction of sensing platform with simple operation,low cost,high sensitivity,and portability has become the main research direction.Based on the advantages of low-cost,operability and high biocompatibility of cellulose paper,the development of a new PEC sensing system combined with high-performance photosensitive materials and sensor recognition strategies is expected to achieve rapid and sensitive detection of biomolecules.In this paper,a variety of wide-spectrum-responsive photoelectrochemical nanomaterials were modified on the surface of cellulose paper based on advantages of Yu group in the photosensitive materials preparation.Besides,nanohybrid-based technology and energy transfer-regulated strategies were also introduced to construct well-performed paper-based photoelectrochemical biosensing device,realizing accurate detection of various biomolecules.The main research has been carried out as follows:（1）Liquid exfoliation method was employed for preparation of wide-spectrum-responsive black phosphorous quantum dots and matched energy levels also played an essential role in constructing black phosphorous quantum dots/titanium dioxide heterojunctions,expanding absorption range of nanomaterials in UV-visible region.Nanocubic cuprous oxide was first coated on PWE by the light-induced photochemical synthesis approach,which then gradually transformed into branched sheet embedded cuprous oxide/copper oxide composites with in-situ conversion strategies.Well-designed overall architecture had a positive impact on higher separation efficiency of photogenerated electrons and holes,laying the foundation for the construction of high-performance photoelectrochemical interfaces;（2）Gold nanoparticles was introduced to fabricate high-performance sensing platform with black phosphor quantum dot/titanium dioxide,where the emission spectra of heterojunction had sufficient overlap with the absorption spectra of the plasmon band of gold nanoparticles.By controlling the distance between them,energy transfer in the PEC sensing process was regulated.A paper-based sensing platform with adjustable distance between nanomaterials was fabricated to realize the sensitive detection of prostate antigen.（3）The paper chip with spatially separated two working electrodes was designed by wax printing approach.Based on branched sheet embedded copper-based nanocubes which displayed desirable initial amplified PEC signal,adjustable distance between electron acceptor G-quadruplex/hemin and interface materials realized switchover from off to on mode of PEC signal.Aptamer labelled with Cu Mn double-doped cerium dioxide acted as visual signal probe,where Cu Mn double-doped cerium dioxide could catalyze 3,3′,5,5′-tetramethylbenzidine to convert colorless to blue in the presence of H₂O₂.Based on above mentioned,an integrated dual signal bioassay was designed to achieve visual prediction and ultrasensitive PEC detection of thrombin.