A Single/dual Photoelectrode Self-powered Sensor Based On In₂O₃-MgIn₂S₄ Composite For Atrazine Detection

Atrazine（ATZ）is one of the triazine herbicide,which is potentially harmful to the growth and development of aquatic plants,animals and human cells.Among the many methods for detecting ATZ,the excitation source required by photoelectrochemical（PEC）analysis could convert the generated optical response into measurable signals under visible light.The photocatalytic fuel cell（PFC）sensor has attracted wide attention due to the miniaturization,portability and high cost performance of sensors.Compared with the traditional three-electrode system,the photoelectric chemical detection could be realized with only two electrodes.The sensor uses photoactive semiconductor material as photoanode,which could absorb light energy and convert it into electric energy.It has the advantages of excellent power output performance,direct electron transfer,no need for biocatellator,stable physical and chemical properties,etc.Metal-organic framework（MOFs）were kinds of structure supported by organic ligands and metal-oxygen clusters,which had attracted wide attention.In recent years,MOFs have proved to be an ideal sacrificial template for the preparation of porous metal oxides or carbon nanostructures by thermal decomposition in a controlled atmosphere.Because the porosity and long-range ordering can provide a fast and convenient passage for small molecules and ions to and from the conversion process.In this paper,In-MOF is used as sacrificing-template to prepare photoelectric functional materials,and different PFC stations are constructed for fast and sensitive detection of ATZ in actual samples.The main research contents are as follows:（1）In₂O₃ nanotubes were prepared by calcination at high temperature using In-MOF as sacrificative template.Based on this,the photoactive material In₂O₃-Mg In₂S₄was prepared as the substrate of photoanode,and the aptamer with excellent specificity was used as recognition technology to construct a highly sensitive and selective PFC sensor for ATZ detection.The constructed sensor platform has a wide linear range in the range of 50-5×10⁵ pmol/L,and the detection limit is as low as 0.04 pmol/L,which has good selectivity,stability and accuracy in the detection of actual samples.This paper provides innovative inspiration for the wide application of PFC sensor platform in the detection of actual samples.（2）The n-type semiconductor In₂O₃-MgIn₂S₄ photoactive material was used as substrate of photoanode,p-type semiconductor Cu In S₂-Cu₂O photoactive material was used as substrate of photocathode,and specific aptamer was used as recognition technology.The novel dual optical electrode PFC and capacitance-amplified aptamer sensor were constructed.Under optimal conditions,theΔP/P₀ and the concentration of ATZ has a wide linear range in the range of 5×10^-2-5×10⁵ pmol/L,and the detection limit is as low as 0.45 pmol/L.TheΔIsc/I₀ and the concentration of ATZ with capacitance amplification has a wide linear range in the range of 4×10^-2 pmol/L-5×10⁵pmol/L,and the detection limit is as low as 0.052 pmol/L.The constructed PFC sensor with dual optical electrode and self-powered aptamer sensor with capacitor amplification provide innovative inspiration for the fusion of capacitor amplification signal and PFC,and has unique advantages such as miniaturization and portability.In this paper,In₂O₃ was prepared by using In-MOF as sacrificial template and calcining In-MOF at high temperature.A photoactive material with excellent properties was prepared based on In₂O₃ as a photoelectric substrate.Two different types of PFC aptamer sensors were constructed.Then,through the phase structure characterization of the prepared material,it was shown that the prepared composite material has a good carrier separation efficiency,and the photoelectric performance test proves that the excellent performance of the photoelectric functional material improves the sensitivity of the sensor.At the same time,as recognition element specific recognition ATZ technology,aptamer improved the selectivity of sensor.The different models of PFC aptamer sensors constructed in this paper show excellent performance,providing a new platform for fast and sensitive ATZ detection.