AuNPs-based colorimetric assay for identification of chicken tissues in meat and meat products

Abstract

A simple colorimetric assay was developed to identify chicken tissues in meat and meat products by utilizing thiol-labeled primers and unmodified gold nanoparticles (AuNPs). Primers were designed based on the chicken-specific mitochondrial D-loop gene. Polymerase chain reaction (PCR) is applied to amplify the target gene, and the PCR products labeled with thiol at one end were obtained. Following the mixing of AuNPs with the PCR products, the thiol binds to the surface of AuNPs, resulting in the formation of GNP-PCR products. The resultant PCR products had abundant negative charges, which made AuNPs maintain dispersion under the role of electrostatic repulsion. As a result, in the presence of PCR products, AuNPs remained red in the presence of salt. In the absence of PCR products, the color of AuNPs changed from red to blue; therefore, the method described here could be exploited for the verification of chicken tissues with high accuracy.