Development of a novel nucleic acid aptamer biosensor for quick and sensitive detection of chlorpyrifos pesticide residues in food

With the continuous pursuit of a better life and health, the accurate and rapid analysis and detection of trace amounts organophosphorus pesticides (OPs) in food products have become increasingly urgent and important. Herein, NaYF 4 :Yb 3+ , Tm 3+ was synthesised by the solvothermal method, and citric acid (CIT) was modified on its surface, the coupling of CIT-NaYF 4 :Yb 3+ , Tm 3+ and chlorpyrifos aptamers, AuNPs coupled to chlorpyrifos cDNA. Fluorescence resonance energy transfer occurs between CIT-NaYF 4 :Yb 3+ , Tm 3+ and AuNPs, resulting in fluorescence quenching. When chlorpyrifos is present in the system, it opens up the complementary strand between the two and leads to the recovery of fluorescence. Under optimal conditions, the sensor shows good linearity in the range of 0.1–200 ng/mL, with a detection limit of 0.051 ng/mL. The proposed method is sensitive, accurate and rapid for the detection of chlorpyrifos residues in food. • A nucleic acid aptamer biosensor was constructed to detect chlorpyrifos. • This sensor has good specificity and anti-interference ability. • This sensor has high sensitivity and low detection limit for chlorpyrifos. • This sensor was applied for accurate quantification of chlorpyrifos in real samples.