Smartphone-Based Quantitative Detection of Ochratoxin A in Wheat via a Lateral Flow Assay

Ochratoxin A (OTA) poses a severe health risk to livestock along the food chain. Moreover, according to the International Agency for Research on Cancer, it is also categorized as being possibly carcinogenic to humans. The lack of intelligent point-of-care test (POCT) methods restricts its early detection and prevention. This work establishes a smartphone-enabled point-of-care test for OTA detection via a fluorescent lateral flow assay within 6 min. By using a smartphone and portable reader, the assay allows for the recording and sharing of the detection results in a cloud database. This intelligent POCT provided (iPOCT) a linearity range of 0.1-3.0 ng/mL and a limit of detection (LOD) of 0.02 ng/mL (0.32 µg/kg in wheat). By spiking OTA in blank wheat samples, the recoveries were 89.1-120.4%, with a relative standard deviation (RSD) between 3.9-9.1%. The repeatability and reproducibility were 94.2-101.7% and 94.6-103.4%, respectively. This work provides a promising intelligent POCT method for food safety.