title: Sensitive electrochemical microbial biosensor for p-nitrophenylorganophosphates based on electrode modified with cell surface-displayed organophosphorus hydrolase and ordered mesopore carbons.
abstract: A novel electrochemical microbial biosensor for the rapid monitoring of p-nitrophenyl-substituted organophosphates (OPs) compounds based on glass carbon electrode (GCE) modified with both ordered mesopore carbons (OMCs) and cell surface-expressed organophosphorus hydrolase (OPH) (OPH-bacteria/OMCs/GCE) was described in this paper. The genetically engineered Escherichia coli strain surface displayed mutant OPH (S5) with improved enzyme activity and favorable stability was constructed using a newly identified N-terminal of ice nucleation protein as an anchoring motif, which can be used directly without further time-consuming enzyme-extraction and purification, thereafter greatly improved the stability of the enzyme. Compared to OPH-bacteria modified GCE (OPH-bacteria/GCE), the OPH-bacteria/OMCs/GCE not only significantly enhanced the current response but also reduced the oxidation overpotential towards oxidizable p-nitrophenol (p-NP), which was the hydrolysate of p-nitrophenyl-substituted OPs. Under the optimized experimental conditions, at +0.84 V (vs. SCE), the current-time curve was performed with varying OPs concentration. The current response was linear with paraoxon concentration within 0.05-25 μM. Similarly, linear range of 0.05-25 μM was found for parathion, and 0.08-30 μM for methyl parathion. The low limits of detection were evaluated to be 9.0 nM for paraoxon, 10nM for parathion and 15 nM for methyl parathion (S/N=3). Thus, a highly specific, sensitive and rapid microbial biosensor was established, which holds great promise for on-site detection of trace p-nitrophenyl-substituted OPs.
authors.affiliation: Laboratory for Biosensing, Qingdao Institute of Bioenergy & Bioprocess Technology, and Key Laboratory of Bioenergy, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China, and University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
authors.forename: Xiangjiang
authors.initials: X
authors.lastname: Tang
authors.affiliation: Laboratory for Biosensing, Qingdao Institute of Bioenergy & Bioprocess Technology, and Key Laboratory of Bioenergy, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China, and University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China; College of Chemistry and Chemical Engineering, Ocean University of China, 238 Songling Road, Qingdao 266100, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Laboratory for Biosensing, Qingdao Institute of Bioenergy & Bioprocess Technology, and Key Laboratory of Bioenergy, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China, and University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Liang
authors.affiliation: Laboratory for Biosensing, Qingdao Institute of Bioenergy & Bioprocess Technology, and Key Laboratory of Bioenergy, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China, and University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
authors.forename: Dongfei
authors.initials: D
authors.lastname: Han
authors.affiliation: Institute of Advanced Energy Materials, Fuzhou University, Fuzhou, Fujian 350002, China.
authors.forename: Lingxing
authors.initials: L
authors.lastname: Zeng
authors.affiliation: Institute of Advanced Energy Materials, Fuzhou University, Fuzhou, Fujian 350002, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zheng
authors.affiliation: College of Chemistry and Chemical Engineering, Ocean University of China, 238 Songling Road, Qingdao 266100, China.
authors.forename: Tie
authors.initials: T
authors.lastname: Li
authors.affiliation: Institute of Advanced Energy Materials, Fuzhou University, Fuzhou, Fujian 350002, China.
authors.forename: Mingdeng
authors.initials: M
authors.lastname: Wei
authors.affiliation: Laboratory for Biosensing, Qingdao Institute of Bioenergy & Bioprocess Technology, and Key Laboratory of Bioenergy, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China, and University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China. Electronic address: liuah@qibebt.ac.cn.
authors.forename: Aihua
authors.initials: A
authors.lastname: Liu
mesh_terms: D001681:Biological Assay / Q000295:instrumentation*; D015374:Biosensing Techniques / Q000295:instrumentation*; D002244:Carbon / Q000737:chemistry*; D002462:Cell Membrane / Q000378:metabolism; D061505:Cell Surface Display Techniques; D003217:Conductometry / Q000295:instrumentation*; D004566:Electrodes; D004784:Environmental Monitoring / Q000295:instrumentation; D004785:Environmental Pollutants / Q000032:analysis / Q000494:pharmacology; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology*; D009596:Nitrophenols / Q000008:administration & dosage* / Q000494:pharmacology*; D009943:Organophosphorus Compounds / Q000008:administration & dosage* / Q000494:pharmacology*; D016062:Porosity; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D004785:Environmental Pollutants; D009596:Nitrophenols; D009943:Organophosphorus Compounds; C008644:nitrophenylphosphate; D002244:Carbon
keywords: Amperometric detection; Bacterial surface display; Electrochemical microbial biosensor; Ordered mesoporous carbons; Organophosphorus hydrolase; p-nitrophenyl organophosphates