Sensors 2011, 11(3), 2728-2739; https://doi.org/10.3390/s110302728
Subtractive Inhibition Assay for the Detection of E. coli O157:H7 Using Surface Plasmon Resonance
College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310029, Zhejiang, China
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Received: 8 January 2011 / Revised: 29 January 2011 / Accepted: 21 February 2011 / Published: 1 March 2011
(This article belongs to the Section Biosensors)
Abstract
A surface plasmon resonance (SPR) immunosensor was developed for the detection of E. coli O157:H7 by means of a new subtractive inhibition assay. In the subtractive inhibition assay, E. coli O157:H7 cells and goat polyclonal antibodies for E. coli O157:H7 were incubated for a short of time, and then the E. coli O157:H7 cells which bound antibodies were removed by a stepwise centrifugation process. The remaining free unbound antibodies were detected through interaction with rabbit anti-goat IgG polyclonal antibodies immobilized on the sensor chip using a BIAcore 3000 biosensor. The results showed that the signal was inversely correlated with the concentration of E. coli O157:H7 cells in a range from 3.0 × 104 to 3.0 × 108 cfu/mL with a detection limit of 3.0 × 104 cfu/mL. Compared with direct SPR by immobilizing antibodies on the chip surface to capture the bacterial cells and ELISA for E. coli O157:H7 (detection limit: both 3.0 × 105 cfu/mL in this paper), the detection limit of subtractive inhibition assay method was reduced by one order of magnitude. The method simplifies bacterial cell detection to protein-protein interaction, which has the potential for providing a practical alternative for the monitoring of E. coli O157:H7 and other pathogens. View Full-TextKeywords:
subtractive inhibition assay; SPR; E. coli O157:H7
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Wang, Y.; Ye, Z.; Si, C.; Ying, Y. Subtractive Inhibition Assay for the Detection of E. coli O157:H7 Using Surface Plasmon Resonance. Sensors 2011, 11, 2728-2739.