A novel nanocomposite optosensing sensor based on porous molecularly imprinted polymer and dual emission quantum dots for visual and high selective detection of bovine serum albumin

A novel dual-emission fluorescence molecularly imprinted polymers (FL-MIPs) sensor was firstly constructed by mixing the green-emission fluorescence molecularly imprinted polymers (g-MIPs) and red-emission CdS/CdTe QDs (r-QDs) in proper proportion, which has been realizing the naked-eye detection of bovine serum albumin (BSA). The fluorescence of g-MIPs gradually turned off and red fluorescence remained after combining with BSA. The thickness of imprinted layer and the ratio of g-MIPs and r-QDs were investigated in detail so as to achieve the optimal performances of FL-MIPs sensor. Meanwhile, the Box-Behnken statistical design was used to optimize the crucial parameters that had an impact on the adsorption effect. Under optimal conditions, the FL-MIPs sensor had excellent linear relationship within 2-64 mu M, and showed the fluorescence color changing from yellow-green to yellow to light pink to red, which achieved the visual detection. The outstanding visual effect of the FL-MIPs sensor made the detection of BSA convenient without too many requirements for equipment and the level of testing personnel except a portable ultraviolet lamp. The limit of detection (LOD) of BSA was 0.5 mu M lower than that of most reported methods. Furthermore, the FL-MIPs sensor can successfully be used to detect BSA in milk, milk powder, human serum and calf serum, with the prefect spiked recoveries of 95.9-104.8%. The numerous advantages make the FL-MIPs sensor have great applicable potential in various fields.