Mn-doped ZnS QDs entrapped in molecularly imprinted membranes for detection of trace bisphenol A

This paper demonstrates a new strategy for producing fluorescent molecularly imprinted membranes (MIMs) for specific recognition of a target molecule. 3-Mercaptopropyltriethoxysilane-capped quantum dots (QDs) were first incorporated into hydrogel membranes of acrylamide and N,N′-methylenediacrylamide to fabricate QD-entrapped molecularly imprinted membranes. The fluorescence intensity of the QDs entrapped in the hydrogel membrane was quenched after being activated by the electron transfer between the QDs and bisphenol A. The quenched fluorescence emission intensity was proportional to the concentration of bisphenol A. Herein, trace levels of bisphenol A were rapidly detected through the quenching of the fluorescence intensity of the QD-entrapped membranes without any preconcentration processes. The linear detection ranges from 0.005 μM to 0.1 μM and with recoveries of 92-108% for bisphenol A. The QD-entrapped hydrogel membranes also showed quite good selectivity for the detection of bisphenol A.