Detection of organophosphorus pesticides using potentiometric enzymatic membrane biosensor based on methylcellulose immobilization.
In this research, a new potentiometric enzymatic membrane biosensor for the detection of organophosphorus pesticides (OPs) was constructed. The basic element of this biosensor was a pH electrode modified with an immobilized acetylcholinesterase layer formed by entrapment with methylcellulose, N,N-dimethylformamide, and bovine serum albumin. The response characteristics of the biosensor were measured and discussed. It was shown that there is a good linear relationship between the inhibition rate and the negative logarithm of OPs concentration in the range from 10(-7) to 10(-5) mol/L, with the detection limits of 10(-7) mol/L for the five pesticides. Moreover, the biosensor could resist the disturbances of below 10(-6) mol/L of Cu(2+) and Pb(2+), and below 10(-5) mol/L of Cd(2+). In addition, the measurement results obtained by the biosensor method were in good agreement with those obtained by the gas chromatography method. This method was successfully applied to detect OPs that remained in the potted lettuce.
College of Resources and Environment, Southwest University, Chongqing 400716, PR China. jzhzhang@swu.edu.cn
Jinzhong
J
Zhang
Aimin
A
Luo
Ping
P
Liu
Shaping
S
Wei
Guomin
G
Wang
Shiqiang
S
Wei
D000110:Acetylcholinesterase / Q000737:chemistry / Q000378:metabolism; D015374:Biosensing Techniques / Q000379:methods*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D018545:Lactuca / Q000737:chemistry; D008567:Membranes, Artificial; D008747:Methylcellulose / Q000737:chemistry* / Q000378:metabolism; D009943:Organophosphorus Compounds / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D011199:Potentiometry / Q000379:methods*; D015203:Reproducibility of Results
D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D009943:Organophosphorus Compounds; D010575:Pesticides; D008747:Methylcellulose; D000110:Acetylcholinesterase