In situ electrodeposited nanoparticles for facilitating electron transfer across self-assembled monolayers in biosensor design.
Gold nanoparticles (AuNPs) were synthesized in situ and electrodeposited onto Au substrate. The AuNPs modified interface facilitates electron transfer across self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid (MUA). After activation of surface carboxyl groups with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide, the interface displayed good stability for immobilization of biomolecules. These modification processes were characterized by contact angle measurement, cyclic voltammetry and electrochemical impedance spectra. The immobilized acetylcholinesterase (AChE), as a model, showed excellent activity to its substrate, leading to a stable AChE biosensor. Under the optimal experimental conditions, the inhibition of malathion on AChE biosensor was proportional to its concentration in two ranges, from 0.001 to 0.1 microg mL(-1) and from 0.1 to 25 microg mL(-1), with detection limit of 0.001 microg mL(-1). The simple method showed good reproducibility and acceptable stability, which had potential application in biosensor design.
Du
Dan
D
Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
Ding
Jiawang
J
Cai
Jie
J
Zhang
Jianming
J
Liu
Li
L
D000110:Acetylcholinesterase / Q000378:metabolism; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004563:Electrochemistry; D004583:Electrons; D004800:Enzymes, Immobilized; D004867:Equipment Design; D006046:Gold; D053768:Metal Nanoparticles; D015203:Reproducibility of Results; D013379:Substrate Specificity
D004800:Enzymes, Immobilized; D006046:Gold; D000110:Acetylcholinesterase