A Lateral Flow Strip Based Aptasensor for Detection of Ochratoxin A in Corn Samples.

Guilan Zhang,Chao Zhu,Jiao Yan,Ailiang Chen,Yafei Huang

doi:10.3390/molecules23020291

Abstract

Ochratoxin A (OTA) is a mycotoxin identified as a contaminant in grains and wine throughout the world, and convenient, rapid and sensitive detection methods for OTA have been a long-felt need for food safety monitoring. Herein, we presented a new competitive format based lateral flow strip fluorescent aptasensor for one-step determination of OTA in corn samples. Briefly, biotin-cDNA was immobilized on the surface of a nitrocellulose filter on the test line. Without OTA, Cy5-labeled aptamer combined with complementary strands formed a stable double helix. In the presence of OTA, however, the Cy5-aptamer/OTA complexes were generated, and therefore less free aptamer was captured in the test zone, leading to an obvious decrease in fluorescent signals on the test line. The test strip showed an excellent linear relationship in the range from 1 ng·mL−1 to 1000 ng·mL−1 with the LOD of 0.40 ng·mL−1, IC15 value of 3.46 ng·mL−1 and recoveries from 96.4% to 104.67% in spiked corn samples. Thus, the strip sensor developed in this study is an acceptable alternative for rapid detection of the OTA level in grain samples.

Highlights

Ochratoxin A (OTA), a mycotoxin produced from species of fungi including Penicillium verrucosum, Aspergillus ochraceus, Aspergillus carbonarius and Aspergillus niger [1,2], could be found in many improperly stored food and agricultural products [3] such as coffee [4], beer [5] and wine [6,7]
OTA detection in food is usually performed using instruments, such as high-performance liquid chromatography (HPLC) [17], ultra-performance liquid chromatography with fluorescence detector (UPLC-FLD) [18], ultra-fast liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UFLC-ESI-MS/MS) [19], gas chromatography-mass spectrometry (GC-MS) [20] and liquid chromatography-mass spectrometry (LC-MS) [21]
Simple, specific, sensitive, and applied Cy5-labeled aptamer based lateral flow strip biosensors in the competitive format were developed for detection of OTA

Summary

Introduction

Ochratoxin A (OTA), a mycotoxin produced from species of fungi including Penicillium verrucosum, Aspergillus ochraceus, Aspergillus carbonarius and Aspergillus niger [1,2], could be found in many improperly stored food and agricultural products [3] such as coffee [4], beer [5] and wine [6,7]. OTA detection in food is usually performed using instruments, such as high-performance liquid chromatography (HPLC) [17], ultra-performance liquid chromatography with fluorescence detector (UPLC-FLD) [18], ultra-fast liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UFLC-ESI-MS/MS) [19], gas chromatography-mass spectrometry (GC-MS) [20] and liquid chromatography-mass spectrometry (LC-MS) [21]. They have good accuracy and reproducibility, they cannot be widely used for rapid onsite detection

Objectives

Methods

Results

Conclusion