Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10429438 | Biosensors and Bioelectronics | 2011 | 5 Pages |
Abstract
We propose a new type of photosensitive biosensor with a CMOS compatible Si photodiode integrated circuit, for the high-sensitive detection of small mycotoxin molecules requiring competitive assay approach. In this work, a photodiode is connected to the gate of a field effect transistor (FET) so that the open circuit voltage (VOC) of the illuminated photodiode is transferred into the drain/source current (IDS) of the FET. The sensing scheme employs competitive binding of toxin molecules (within the sample solution) and toxin-BSA conjugates (immobilized on the photodiode surface) with Au-nanoparticle-labeled antibodies, followed by silver enhancement to generate opaque structures on the photodiode surface. By utilizing the non-linear dependence of the VOC on the light intensity, we can maintain a sufficiently high signal resolution at low toxin concentrations (with most of the incident light blocked) for the competitive assay. By monitoring the IDS of the FET whose gate is driven by the VOC, quantitative detection of Aflatoxin B1 has been achieved in the range of 0-15Â ppb.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Chan Woo Park, Jong-Heon Yang, Chil Seong Ah, Chang-Geun Ahn, Yo Han Choi, Kwang Hyo Chung, Wan-Joong Kim, Gun Yong Sung,