Rapid determination of atrazine in apple juice using molecularly imprinted polymers coupled with gold nanoparticles-colorimetric/SERS dual chemosensor

Rapid and reliable determination of atrazine, a common chemical contaminant, in agri-foods is highly necessary. We reported a novel dual-chemosensor coupling, a separation [molecularly imprinted polymers (MIPs)], an instrumental-free detection [gold nanoparticles (AuNPs)-based colorimetric assay] and an instrument-based quantification [surface enhanced Raman spectroscopy (SERS)] method for high-throughput and sensitive determination of atrazine in apple juice. Used as the selective sorbent for the solid phase extraction, MIPs effectively extracted atrazine from apple juice with high recoveries (similar to 93%). AuNPs of different sizes (large; medium; and small) performed differently in the two analytical methods. Large-AuNPs provided the highest sensitivity in colorimetric analysis (< 0.01 mg L-1), while medium-AuNPs achieved the lowest limit of detection (0.0012 mg L-1) and quantification (0.0040 mg L-1) in SERS analysis. With minor modifications, protocols for both analytical methods can rapidly detect and/or quantify atrazine in different food products complying with the Health Canada regulation (0.005 mg L-1).