Studies On Nano-modified Amperometric Enzyme Biosensor And Its Application In Pesticide Residue Analysis

Enzymes are the most powerful molecular recognition elements in biosensing,since the sensing signal can be amplified millions of times through enzymatic reactions.This signal amplification enables the designing of highly sensitive biosensing systems. Amperometdc enzymatic biosensors have been considered to be the most suitable for biochemical analysis due to their good selectivity,,sensitivity,rapid response,miniature size,and reproducible results.A combination of enzymatic reactions with electrochemical method allowed to develop different enzyme based electrochemical biosensors for sensitive and rapid determination of environmental analysis.Among these,amperometric acetylcholinesterase(AChE) biosensors based on the inhibition of AChE have shown satisfactory results for pesticides analysis,in which the enzymatic activity is employed as an indicator of quantitative measurement of insecticides.And amperometric organophosphorous hydrolase(OPH) biosensors based on degrade organophosphates have also shown satisfactory results for pesticides analysis,in which the current is employed as an indicator of quantitative measurement of insecticides.A significant challenge to development of sensitive and stable sensors comes from effective immobilization of enzyme to solid electrode surface.This will directly affect the stability,sensitivity,detection limit and the response time of the sensor,and affect the enzyme activity and the survival time of the enzyme.The immobilization technologies of biosensor enzyme include the immobilization methods and carrier material selection.The immobilization technologies of biosensor enzyme have attracted enormous research in recent years and made much important progress.In our experiment,on the one hand,the nanoparticles modified amperometric acetylcholinesterase(ACHE) biosensors have been fabricated and used for detecting the carbamate pesticides and the organophosphate pesticides.On the other hand,the nanoparticles modified amperometric organophosphorous hydrolase(OPH) biosensors have been also fabricated and used for detecting the carbamate pesticides and the organophosphate pesticides.To sum up,these proposed ACHE and OPH biosensors could be readily extended toward the determination of pesticide and the investigation of medicine or pesticide sensitivity.