An Alkyne-Mediated SERS Aptasensor for Anti-Interference Ochratoxin A Detection in Real Samples

Hao Wang; Lu Chen; Min Li; Yongxin She; Chao Zhu; Mengmeng Yan

doi:10.3390/foods11213407

An Alkyne-Mediated SERS Aptasensor for Anti-Interference Ochratoxin A Detection in Real Samples

Foods. 2022 Oct 28;11(21):3407. doi: 10.3390/foods11213407.

Authors

Hao Wang^{1

2}, Lu Chen^{1

2}, Min Li^{1

2}, Yongxin She³, Chao Zhu^{1

2}, Mengmeng Yan^{1

2}

Affiliations

¹ Institute of Quality Standard and Testing Technology for Agro-Products, Shandong Academy of Agricultural Sciences, Jinan 250100, China.
² Shandong Provincial Key Laboratory Test Technology on Food Quality and Safety, Jinan 250100, China.
³ Institute of Quality Standard and Testing Technology for Agro-Products, Chinese Academy of Agricultural Science, Beijing 100081, China.

Abstract

Avoiding interference and realizing the precise detection of mycotoxins in complex food samples is still an urgent problem for surface-enhanced Raman spectroscopy (SERS) analysis technology. Herein, a highly sensitive and specific aptasensor was developed for the anti-interference detection of Ochratoxin A (OTA). In this aptasensor, 4-[(Trimethylsilyl) ethynyl] aniline was employed as an anti-interference Raman reporter to prove a sharp Raman peak (1998 cm^-1) in silent region, which could avoid the interference of food bio-molecules in 600-1800 cm^-1. 4-TEAE and OTA-aptamer were assembled on Au NPs to serve as anti-interference SERS probes. Meanwhile, Fe₃O₄ NPs, linked with complementary aptamer (cApts), were applied as capture probes. The specific binding of OTA to aptamer hindered the complementary binding of aptamer and cApt, which inhibited the binding of SERS probes and capture probes. Hence, the Raman responses at 1998 cm^-1 were negatively correlated with the OTA level. Under the optimum condition, the aptasensor presented a linear response for OTA detection in the range of 0.1-40 nM, with low detection limits of 30 pM. In addition, the aptasensor was successfully applied to quantify OTA in soybean, grape and milk samples. Accordingly, this anti-interference aptasensor could perform specific, sensitive and precise detection of OTA in real samples, and proved a reliable reference strategy for other small-molecules detection in food samples.

Keywords: 4-TEAE; OTA; SERS; anti-interference; aptamer; silent region.

Grants and funding

This work was supported by the National Natural Science Foundation of China (32102088, 32172309), the Natural Science Foundation of Shandong Province (Grant No. ZR2022QB207), Supported by the Taishan Scholars Program, the Young Elite Scientist Sponsorship Program of Beijing Association for Science and Technology, the Agricultural Scientific and Technological Innovation Project of Shandong Academy of Agricultural Sciences (CXGC2018E05, CXGC2021B14, and CXGC2022E05), the Focus on Research and Development Plan in Shandong Province (No. 2020CXGC010804).