| Photoelectrochemical(PEC)sensing is an analytical sensing method based on photoelectric signal conversion to reflect the light-induced electron transfer changes at the electrode/solution interface.However,this analysis method is susceptible to environmental factors such as light intensity,resulting in low accuracy of detection results.Therefore,it is very important to design and develop a PEC sensor that can reduce interference and improve the accuracy of detection results.This paper combines the ratiometric method to design a series of ratio PEC biosensing platforms that can effectively improve the anti-interference ability.The main research work is as follows:1.As a new analytical tool,photoelectrochemical(PEC)biosensors have been extensively studied.However,conventional PEC biosensors typically require a highly stable source of light to excite electrical signals,and signal data require to be collected and processed by electrochemical workstations.,which limits the development of portable PEC devices.Here.,we propose the design of a solar portable PEC biosensor using sunlight as a light source.In order to eliminate the interference caused by changes in sunlight intensity over time and weather,the principle of potential resolution ratio was introduced,and the sensitive and portable PEC sensing platform was successfully applied to the analysis of afnatoxin B1 directly under sunlight and equipped with micro-electrochemical workstation and notebook computer.2.The conductive matrix(ITO)separated from the two regions was modified with Co,N-TiO2/3DGH and prussian blue(PB),respectively,the surface of the region modified with Co,N-TiO2/3DGH in ITOl was functionalized with an aptamer and used as module A for detection and IT02 was directly used as module B for reference.Under illumination,when the target OTA is present,the color of the discolored part of module A varies with target concentration,but the discolored part of module B remains basically only affected by environmental factors such as light intensity,so it can be used as a stable reference.Based on this,the relationship between the gray scale ratio and the density of the color can be obtained and have successfully designed a photo-electrochromism biosensor based on the ratiometric method to avoid the interference of some factors in the detection process and improve the accuracy of the detection result.It can be identified by the naked eye,which provides a great potential for the construction of a fast and convenient electrochemical sensing platform in the future.3.In order to avoid the use of precious metal or heavy metal materials,three-dimensional graphene hydrogel-supported carbon quantum dot nanocomposites(C-dots/3DGH)and graphite phase carbonmtrides(g-C3N4)having excellent PEC activity and matching potential were prepared.By modifying these two materials onto two adjacent regions on the ITO electrode,the cathode current generated by C-dots/3DGH and the anode current generated by g-C3N4 can be clearly distinguished by applying different bias voltages,and will not interfere with each other.In the presence of the target,its binding to the aptamer results in a significant increase in steric hindrance and a significant decrease in cathodic current.At the same time,the anode current generated by g-C3N4 is not affected and can be used as a stable reference for evaluating environmental factors.Therefore,the target(E.coli)can be quantified by the ratio of cathode current to anode current,which effectively eliminates these analyte-independent factors and provides a more accurate analysis.In addition,this ratiometric PEC biosensor also showed good sensitivity and a wide linear range(2.9 cfu/mL to 2.9x106 cf1/mL). |
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