title: Organophosphorus hydrolase multilayer modified microcantilevers for organophosphorus detection.
abstract: We report a biosensor based on organophosphorus hydrolase (OPH) multilayer modified microcantilever (MCL) for detection of organophosphorus compounds (OPs). The assay is based on substrate-dependent bending of the OPH functionalized MCLs. The cantilever bending amplitude at equilibrium was a function of the concentration of paraoxon with the dynamic range extending from 10(-7) to 10(-3)M. The lower detection limit of approximately 10(-7)M for paraoxon was an order of magnitude better than the OPH-based potentiometric and optical biosensors based on pH modulation. There was a good intra-sensor and an acceptable inter-sensor reproducibility as evidenced by the standard errors of 5% and 15%, respectively. OPs measured using this technique included parathion and diisopropyl fluorophosphate (DFP) in the order of paraoxon>DFP>parathion. The conformational change of the OPH was most likely the main origin of MCL bending.
authors.affiliation: Department of Chemistry, Institute for Micromanufacturing, Louisiana Tech University, Ruston, LA 71272, United States.
authors.forename: Chandana
authors.initials: C
authors.lastname: Karnati
authors.forename: Hongwei
authors.initials: H
authors.lastname: Du
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Ji
authors.forename: Xiaohe
authors.initials: X
authors.lastname: Xu
authors.forename: Yuri
authors.initials: Y
authors.lastname: Lvov
authors.forename: Ashok
authors.initials: A
authors.lastname: Mulchandani
authors.forename: Priti
authors.initials: P
authors.lastname: Mulchandani
authors.forename: Wilfred
authors.initials: W
authors.lastname: Chen
mesh_terms: D043303:Aryldialkylphosphatase / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D004548:Elasticity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D019563:Mechanics; D009943:Organophosphorus Compounds / Q000032:analysis* / Q000737:chemistry; D010783:Photometry / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D014159:Transducers
chemical_list: D020099:Coated Materials, Biocompatible; D009943:Organophosphorus Compounds; D043303:Aryldialkylphosphatase