Construction And Application Study Of A Multi-analyte Photo-assisted Self-powered Sensing Platform Based On Copper Photosensitive Materials

In recent years,photo-assisted fuel cell based self-powered sensing detection is a new electrochemical detection technique.Compared with the conventional electrochemical biological sensing detection,it only needs can to be detected object via only single-photoelectrode and dual-photoelectrode.The self-powered sensor based on photo-assisted fuel cell can convert light and chemical energy to electrical energy without additional power supply.It has the advantages of simple equipment,quick detection and low cost.To solve the problems of low photoelectric conversion and detection efficiency,this work selected copper-based nanomaterials with excellent light absorption and high photoelectric conversion efficiency as photocathode materials.Based on fermi level matching principle,a suitable photoanode material was selected to construct a photo-assisted dual-photoelectrode self-powered platform.Furthermore,the sensing platform is constructed by modifying the recognition element on the electrode.It not only realized the high efficiency of photoelectric conversion,but also realized the quantitative analysis of multi-analyte in a detection system.The research contents are as follows:1.The photo-assisted dual-photoelectrode self-powered platform was constructed by solvothermal preparation of nanoflower-like Cu In S₂ nanomaterials as photocathode material and hydrothermal calcination of Ti O₂ nanorods array（Ti O₂ NRs）as photoanode material.The results shown that the maximum output power density(P_max)of the photo-assisted dual-photoelectrode self-powered platform was 9.2μW/cm²,which is 1.7 times of that of the photo-assisted single-photoelectrode self-powered platform P_max（5.4μW/cm²）.Furthermore,the photo-assisted dual-photoelectrode self-powered aptamer sensing platform based on Cu In S₂was constructed by modifying zearalenone（ZEN）aptamer on the photoanode as recognition element.ZEN specifically bound to the aptamer on the photoanode surface,which increased the steric resistance of the photoanode surface,reduced the migration rate of photogenerated electrons,and reduced the photoelectric output signal,achieving the quantitative analysis of ZEN.The logarithm of ZEN concentration showed a good linear relationship in the range of 1.0-5.0×10²ng/m L,and the detection limit was 0.33 ng/m L,which realized the quantitative detection of ZEN in corn samples.The photo-assisted dual-photoelectrode self-powered aptamer sensing platform made full use of the excellent photoelectric conversion efficiency of copper-based nanomaterials to obtain high electrical output signal.2.To further improve the photoelectric conversion efficiency of the photo-assisted dual-photoelectrode self-powered platform,CuSCN NRs was prepared by electrodeposition method as photocathode material and Ti O₂ NRs as photoanode material.The results shown that the photo-assisted dual-photoelectrode self-powered platform constructed by this system has higher electrical output performance,with P_max of 25μW/cm²,2.7 times that of the first work.To improve the detection efficiency,by the aptamers of OTA and AFB1 were modified on the photoanode and photocathode as recognition elements based on the region separation strategy.And it has the advantage of mutual interference generated by two objects effectively.The target and aptamer combined on the electrode surface,and the aptamer is detached from the electrode surface,which accelerated the migration rate of photogenerated electrons and increased the photoelectric output signal,and successfully realized the dual target detection in a same system.In this sensing system,the logarithm of OTA and AFB1 concentration showed a good linear relationship in the range of 1.0×10^-3-5.0×10² ng/m L and 1.0×10^-3-1.0×10³ ng/m L,respectively,with detection limits of 0.33 pg/m L,which realized the quantitative detection of OTA and AFB1in corn samples.This work not only realized the detection of two mycotoxins in corn samples,but also provided a new idea for multi-analyte quantitative analysis.3.On the basis of the above research,the quantitative analysis of multi-analyte in a detection system was further explored.An electrode chip was divided into different regions by laser etching.Zn In₂S₄ was modified in the photoanode region,and Cu₂O/CuO was modified in the photocathode region to obtain a multi-channel chip electrode.Based on the mechanism of spatial resolution strategy,three kinds of porcine diarrhea coronavirus antibodies were used as recognition elements and modified on different photoanode regions respectively,which has the advantage of no mutual interference between recognition reaction and signal output.The target virus specifically bound to the antibodies on the photoanode surface,which increased the steric resistance of the photoanode surface,reduced the migration rate of photogenerated electrons,and reduced the photoelectric output signal,achieving the quantitative analysis of three viruses.In this sensing system,the logarithms of porcine epidemic diarrhea virus（PEDV）,porcine delta coronavirus（PDCo V）and porcine transmissible gastroenteritis virus（TGEV）concentration showed a good linear relationship in the range of 1.0×10²-1.0×10⁵ TCID₅₀/m L,1.0×10³-1.0×10^6.5 TCID₅₀/m L and 1.0×10²-1.0×10⁶ TCID₅₀/m L,respectively,and the detection limits were 33.3 TCID₅₀/m L,333.3 TCID₅₀/m L and 33.3 TCID₅₀/m L,which realized the quantitative detection of three kinds of porcine diarrhea coronavirus in the small intestine.The construction of the sensing platform not only realizes the multi-analyte detection,but also provides a new construction method for the design of the chip based multi-analyte detection sensing platform.