High-performance lateral flow immunoassay using aggregation-induced-emission nanospheres for sensitive detection of lambda-cyhalothrin residue in food

The fluorescence performance of AIEgens was improved after molecular modification. • The new fluorescence LFIA exhibited broad linear range and high sensitivity for LCT detection. • The proposed LFIA is applicable to detect LCT in various food samples. The extensive and widespread use of lambda-cyhalothrin (LCT) has raised concerns over its adverse effects on the environment and human health, highlighting the urgent need for rapid and sensitive detection of LCT residues in food commodities. In this study, a highly sensitive lateral flow immunoassay (LFIA) was developed using novel aggregation-induced-emission (AIE) fluorescent nanospheres for the determination of LCT. Starting from tetraphenylethylene (TPE), a typical AIE luminogen, three derivatives were synthesized via chemical reaction. Among them, tetraldehyde tetraphenylethylene-based fluorescent nanospheres (TAPEFN) exhibited superior optical performance. Following conjugation of TAPEFN with anti-LCT monoclonal antibodies, the resulting TAPEFN-mAb served as an efficient fluorescent probe within the LFIA platform. The established TAPEFN-LFIA exhibited a linear detection range of 3.9 to 500 ng/mL, with a limit of detection of 3.8 ng/mL, which was 4.2-fold lower compared to TPEFN-LFIA (15.85 ng/mL). The reliability of the established method was demonstrated by the detection of spiked food samples, with acceptable recoveries (72.82%–119.34%) and low coefficients of variation (<16.97%). These findings demonstrate that rational molecular engineering can significantly enhance the fluorescence properties of AIE materials, and that the resulting nanospheres provide a powerful signal-reporting strategy for improving LFIA sensitivity. Download: Download high-res image (154KB) Download: Download full-size image