title: Efficient immobilization of acetylcholinesterase onto amino functionalized carbon nanotubes for the fabrication of high sensitive organophosphorus pesticides biosensors.
abstract: This work introduced an efficient immobilization of acetylcholinesterase (AChE) onto amino functionalized carbon nanotubes (CNT-NH2), in order to fabricate high sensitive and practical organophosphorus pesticide (OPs) biosensors. Compared with the pristine, -COOH and -OH decorated CNTs, there were larger amount of enzymes adsorbed on the surface of CNT-NH2 with a favorable orientation and the best amperometric response was obtained on the AChE/CNT-NH2/GC electrode. Furthermore, the biosensor modified with CNT-NH2 showed a high affinity to acetylthiocholine chloride (ATCh) and could catalyze the hydrolysis of ATCh with an apparent Michaelis-Menten constant (Km) value of 67.4 µM. Using paraoxon as a model compound, wide linear ranges from 0.2 nM to 1 nM and 1 nM to 30 nM, and a low detection limit of 0.08 nM were obtained with satisfactory reproducibility and stability. Moreover, the biosensor had also been successfully employed for the determination of low concentrations of pesticides in real vegetable samples. This method could be extended to other functionalized nano-materials for their application in constructing biosensors.
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China; State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China.
authors.forename: Guangxia
authors.initials: G
authors.lastname: Yu
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China; State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China.
authors.forename: Weixiang
authors.initials: W
authors.lastname: Wu
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China; State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China; State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Wei
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China; State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei, 430030, China. Electronic address: qi_weiliao@126.com.
authors.forename: Qing
authors.initials: Q
authors.lastname: Lu
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry / Q000378:metabolism*; D000327:Adsorption; D000586:Amination; D015374:Biosensing Techniques / Q000379:methods*; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D057230:Limit of Detection; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000032:analysis / Q000378:metabolism; D010261:Paraoxon / Q000032:analysis* / Q000378:metabolism; D010575:Pesticides / Q000032:analysis* / Q000378:metabolism; D015203:Reproducibility of Results; D014675:Vegetables / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D009943:Organophosphorus Compounds; D010575:Pesticides; D000110:Acetylcholinesterase; D010261:Paraoxon
keywords: Carbon nanotubes; Organophosphorus pesticide biosensor; Orientation; Paraoxon; Protein adsorption; Surface functionalization