Ascorbic acid-mediated in situ growth of gold nanostars for photothermal immunoassay of ochratoxin A

Yiwen Wang; Longyingzi Xie; Lanrui Ma; Qi Wu; Zhixia Li; Yanlin Liu; Qiyang Zhao; Yaohai Zhang; Bining Jiao; Yue He

doi:10.1016/j.foodchem.2023.136049

Ascorbic acid-mediated in situ growth of gold nanostars for photothermal immunoassay of ochratoxin A

Food Chem. 2023 Sep 1:419:136049. doi: 10.1016/j.foodchem.2023.136049. Epub 2023 Mar 27.

Authors

Yiwen Wang¹, Longyingzi Xie¹, Lanrui Ma¹, Qi Wu¹, Zhixia Li², Yanlin Liu¹, Qiyang Zhao¹, Yaohai Zhang¹, Bining Jiao¹, Yue He³

Affiliations

¹ Key Laboratory of Quality and Safety Control of Citrus Fruits, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing 400712, China; Laboratory of Quality & Safety Risk Assessment for Citrus Products (Chongqing), Ministry of Agriculture and Rural Affairs, Citrus Research Institute, Southwest University, Chongqing 400712, China; National Citrus Engineering Research Center, Chongqing 400712, China.
² Institute of Agro-Products Safety and Nutrition, Tianjin Academy of Agricultural Sciences, Tianjin 300381, China.
³ Key Laboratory of Quality and Safety Control of Citrus Fruits, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing 400712, China; Laboratory of Quality & Safety Risk Assessment for Citrus Products (Chongqing), Ministry of Agriculture and Rural Affairs, Citrus Research Institute, Southwest University, Chongqing 400712, China; National Citrus Engineering Research Center, Chongqing 400712, China. Electronic address: yuehe@cric.cn.

PMID: 37003051
DOI: 10.1016/j.foodchem.2023.136049

Abstract

Currently, the development of efficient mycotoxins detection methods, particularly using portable devices as readout devices, remains a great challenge. Herein, a photothermal enzyme-linked immunosorbent assay (ELISA) based on gold nanostars (AuNSs) for the detection of ochratoxin A (OTA) using a "thermometer" was proposed for the first time. AuNSs with photothermal conversion capacity were parepared using an ascorbic acid (AA)-mediated in situ growth methd. Quantification was based on the alkaline phosphatase catalyzing the dephosphorylation of ascorbic acid 2-phosphoate to AA, thereby converting OTA concentration to the amount of in situ synthesized AuNSs, thus achieving straightforward readout by temperature. Benefiting from the classical tyramine signal amplification strategy, a detection limit of 0.39 ng mL^-1 was obtained. The recoveries of grape juice and maize samples spiked with 10 ng mL^-1 and 30 ng mL^-1 OTA ranged from 86.53% to 116.9%. Our method has great potential in on-site OTA detection for food safety.

Keywords: Gold nanostars; Ochratoxin A; Photothermal immunoassay; Portable detection; Tyramine signal amplification.

MeSH terms

Gold
Immunoassay / methods
Limit of Detection
Mycotoxins* / analysis
Ochratoxins* / analysis

Substances

ochratoxin A
Gold
Ochratoxins
Mycotoxins