title: Mussel adhesive protein-based whole cell array biosensor for detection of organophosphorus compounds.
abstract: A whole cell array biosensor for the efficient detection of neurotoxic organophosphate compounds (OPs) was developed through the immobilization of recombinant Escherichia coli cells containing periplasmic-expressing organophosphorus hydrolase (OPH) onto the surface of a 96-well microplate using mussel adhesive protein (MAP) as a microbial cell-immobilizing linker. Both the paraoxon-hydrolyzing activity and fluorescence microscopy analyses demonstrated that the use of MAP in a whole cell biosensor increased the cell-immobilizing efficiency and enhanced the stability of immobilized cells compared to a simple physical adsorption-based whole cell system. Scanning electron microscopic analyses also showed that the E. coli cells were effectively immobilized on the MAP-coated surface without any pretreatment steps. The whole cell array biosensor system, prepared using optimal MAP coating (50 μg/cm(2)) and cell loading (4 OD(600)), detected paraoxon levels as low as 5 μM with high reproducibility, and its quantitative detection range was ~5-320 μM. The MAP-based whole cell array biosensor showed a good long-term stability for 28 day with 80% retained activity and a reusability of up to 20 times. In addition, paraoxon in tap water was also successfully detected without a reduction in sensitivity. Our results indicate that the proposed MAP-based whole cell array system could be used as a potential platform for a stable and reusable whole cell biosensor.
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea.
authors.forename: Chang Sup
authors.initials: CS
authors.lastname: Kim
authors.forename: Bong-Hyuk
authors.initials: BH
authors.lastname: Choi
authors.forename: Jeong Hyun
authors.initials: JH
authors.lastname: Seo
authors.forename: Geunbae
authors.initials: G
authors.lastname: Lim
authors.forename: Hyung Joon
authors.initials: HJ
authors.lastname: Cha
mesh_terms: D001681:Biological Assay / Q000295:instrumentation*; D015374:Biosensing Techniques / Q000295:instrumentation*; D002448:Cell Adhesion / Q000502:physiology; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology*; D017022:Flow Injection Analysis / Q000295:instrumentation*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D009943:Organophosphorus Compounds / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology*; D011506:Proteins / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D009943:Organophosphorus Compounds; D011506:Proteins; C037403:adhesive protein, mussel