Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10429565 | Biosensors and Bioelectronics | 2005 | 9 Pages |
Abstract
A quartz crystal microbalance (QCM) immunosensor was described for the detection of Salmonella Typhimurium with simultaneous measurements of the resonant frequency and motional resistance. The immunosensor was fabricated using protein A for the antibody immobilization. High-frequency impedance analysis indicated that the changes in resonant frequency and motional resistance (ÎF and ÎR) of the QCM were significant while the changes in static capacitance, motional capacitance, and motional inductance were insignificant. In the direct detection of S. Typhimurium in chicken meat sample, ÎF and ÎR were proportional to the cell concentration in the range of 105-108 and 106-108Â cells/ml, respectively. Using anti-Salmonella-magnetic beads as a separator/concentrator for sample pretreatment as well as a marker for signal amplification, the detection limit was lowered to 102Â cells/ml based on the ÎR measurement; however, ÎF was not related to the cell concentration. No interference was observed from E. coli K12 or the sample matrix.
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Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Xiao-Li Su, Yanbin Li,