Development and application of fluorescence sensor and test strip based on molecularly imprinted quantum dots for the selective and sensitive detection of propanil in fish and seawater samples

Molecularly imprinted quantum dots (MIP-QDs) were successfully synthesized via reversed-phase microemulsion and used as the specific recognition element and signal probe of a fluorescence sensor or test strip to achieve the highly sensitive detection of propanil. The physical–chemical characteristics and excellent selectivity of MIP-QDs were elucidated. Under optimized parameters, the MIP-QDs had good linearity at the propanil concentration range of 1.0 μg/L to 20.0 × 103 μg/L by fluorescence quenching. The developed MIP-QD-based fluorescence sensor showed good recoveries ranging from 87.2 % to 112.2 %, and the relative standard deviation was below 6.0 % for the fish and seawater samples. In addition, the limits of detection (LODs) for fish and seawater were 0.42 μg/kg and 0.38 μg/L, respectively. The fluorescence test strip developed on the basis of the MIP-QDs also displayed satisfactory recoveries of 90.1 %–111.1 %, and the LOD for propanil in the seawater sample was 0.6 μg/L. The proposed fluorescence sensor and test strip were successfully used in propanil determination in environment and aquatic products.