Synthesis of Multi-mode Quantum Dots Encoded Molecularly Imprinted Polymers Microspheres and Application in Quantitative Detection for Dopamine

Abstract

As the promising analytical strategy, multi-mode quantum dots (QDs) encoded molecularly imprinted fluorescent sensors have attracted considerable attention. Here, a novel encoding strategy for water-dispersed QDs molecularly imprinted polymers microspheres (MIPMs) with a high-performance fluorescence intensity and multi-color signal was established. The water-compatible MIPMs were firstly synthesized via integrating the reversible addition-fragmentation chain transfer and precipitation polymerization (RAFT-PP), which could improve the water compatibility by grafting the hydrophilic groups of poly(2-hydroxyrthyl methacrylate) (PHEMA). Then the water-compatible MIPMs were used as embedding matrix to separately incorporate with five different QDs, and a series of multi-color QDs encoded MIPs (five single-color and 10 dual-color fluorescent systems) were obtained. The fluorescent characterization of encoded MIPMs was studied in detail. Further, dual-mode fluorescence systems were fabricated as fluorescence sensors for the quantitative detection of dopamine; good linear response in the range of 5-300 μg L-1 and 1-100 μg L-1 and the limit of detection (LOD) with 2 μg L-1 and 0.5 μg L-1 were obtained for monochromatic and ratiometric sensor, respectively. It is the first time to introduce the optical encoding strategy into the fabrication of fluorescent MIPs, which not only greatly simplifies the preparation process of fluorescent imprinted sensor, but also provides more alternatives for the detection method of analyte and the potential of high-throughput multiple analytes at one time.