CdTe_0.5S_0.5/ZnS Quantum Dots Embedded in a Molecularly Imprinted Polymer for the Selective Optosensing of Dopamine

This work describes the preparation of molecularly imprinted polymer (MIP)-modified core/shell CdTe_0.5S_0.5/ZnS quantum dots (QDs). The QDs@MIP particles were used for the selective and sensitive detection of dopamine (DA). Acrylamide, which is able to form hydrogen bonds with DA, and ethylene glycol dimethylacrylate (EGDMA) as cross-linker were used for the preparation of the MIP. Highly cross-linked polymer particles with sizes up to 1 µm containing the dots were obtained after the polymerization. After the removal of the DA template, MIP-modified QDs (QDs@MIP) exhibit a high photoluminescence (PL) with an intensity similar to that of QDs embedded in the nonimprinted polymer (NIP). A linear PL decrease was observed upon addition of DA to QDs@MIP and the PL response was in the linear ranges from 2.63 µM to 26.30 µM with a limit of detection of 6.6 nM. The PL intensity of QDs@MIP was quenched selectively by DA. The QDs@MIP particles developed in this work are easily prepared and of low cost and are therefore of high interest for the sensitive and selective detection of DA in biological samples.