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Updated: Feb 1, 2026

Design and Development of Aptamer–Gold Nanoparticle Based Colorimetric Assays for In-the-field Applications
Published on: June 23, 2016
Sensitive aptamer-based fluorescene assay for ochratoxin A based on RNase H signal amplification
Kefeng Wu1, Changbei Ma1, Han Zhao1
1School of Life Sciences, Central South University, Changsha 410013, China.
Abstract:
A new assay for the selective and sensitive aptamer-based fluorescent biosensor for ochratoxin A (OTA) detection is proposed. It consists of a ribonuclease H (RNase H)-assisted cycle response that leads to a significant amplification of the signal, which allow for a low limit of detection (LOD) of 0.08 ng/mL. By using this technique, a high selectivity for OTA against ochratoxin B and aflatoxin B1 (AFB1) was noticed. The quantitative determination in real samples has been verified using red wine samples spiked with a series of OTA concentrations (0.4, 4, and 12 ng/mL), and the recoveries ranged from 96.1 to 107.5%. This aptasensor has great practical applications in food industry and moreover, can be extended for the detection of other toxins by replacing the sequence of the recognition aptamer.
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