Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7232024 | Biosensors and Bioelectronics | 2015 | 7 Pages |
Abstract
Determination of ochratoxin A (OTA) is highly important for food safety control. In this study, a signal-on electrochemiluminescence (ECL) biosensor which combined the characteristics of high efficiency of hyperbranched rolling circle amplification (HRCA) and high selectivity of aptamer was developed for OTA determination. The capture probe DNA (CDNA) was firstly immobilized on the gold electrode surface through Au-S interaction, then the OTA aptamer was modified on the electrode surface through hybridization with CDNA. Since OTA can competitively bind with the aptamer due to their high affinity, which would induce the releasing of aptamer from the electrode surface. Subsequently, the free CDNA on the electrode surface can hybridize with the padlock probe and induce HRCA reaction subsequently. Thus, the HRCA products which contained large amount of double-stranded DNA (dsDNA) fragments can be accumulated on the electrode surface. Since Ru(phen)32+ can intercalate into the groove of dsDNA and acts as ECL indicator, high ECL intensity can be detected from the electrode surface. The enhanced ECL intensity has a linear relationship with OTA in the range of 0.05-500Â pg/mL with a correlation coefficient of 0.9957, and the limit of detection (LOD) was 0.02Â pg/mL. The developed biosensor has been applied to determine OTA concentration in the corn samples with satisfied results.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Linlin Yang, Ying Zhang, Ruibao Li, Cuiying Lin, Longhua Guo, Bin Qiu, Zhenyu Lin, Guonan Chen,