AuNPs-Based Colorimetric Assay for Identification of Chicken Tissues in Meat and Meat Products

Hejing Han,Tingting Huang,Dongjun Hou,Zhihui Hao,Wen Yi

doi:10.1155/2015/469267

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.

Highlights

Fraudulent ingredients in meat and meat products are a valid concern for various reasons, such as public health, religious factors, and unfair competition in meat market [1]
As depicted in Scheme 1, chicken tissues could be identified with high specificity, sensitivity, and accuracy
In colorimetric assays, the resulting solutions containing thiol-labeled Polymerase chain reaction (PCR) products remained red in color, along with a higher spectral value at 520 nm and a lower spectral value at 650 nm

Summary

Introduction

Fraudulent ingredients in meat and meat products are a valid concern for various reasons, such as public health, religious factors, and unfair competition in meat market [1]. As news reports in 2013 indicated, the incident of animal protein adulteration in Shanghai, China, caused public panic about meat safety. Compared with animal protein sources such as pork and beef, chicken is relatively cheap. Compared with protein, DNAbased methods were more reliable due to their high stability and unique variability that can identify meat tissues from closely related species. Among DNA-based methods, PCR technology with high accuracy and specificity, such as PCRRFLP [4, 5] and the real-time PCR [6, 7], is more popular. These DNA-based methods required relatively tedious procedures and expensive instruments. We attempted to develop a colorimetric assay using AuNPs technology in conjunction with PCR technology

Materials and Methods

Results

Discussion

Conclusions