Development of an optical nanosensor based on TGA-stabilized-CdTe embedded in silica molecularly imprinted polymer for the rapid and selective determination of propranolol

In this work, a fluorimetric sensor based on molecularly imprinted polymers (MIPs) has been developed for the determination of an important drug, propranolol (PROP). The World Health Organization has put PROP on the list of essential medicines [1]. PROP most widely used to treat a wide range of different diseases and disorders [2] . MIPs have cavities which are created during polymerization. These cavities are perfectly matched to their template (analyte) regarding shape, size, functional groups and orientation of cavities. MIPs in various fields have received considerable attentions because of their advantages such as ease of production, cheapness, high stability in different experimental conditions (such as temperatures, pH, and toxic environments) [3]. For preparation of the sensor, water-soluble thioglycolic acid stabilized CdTe QDs (TGA-stabilized CdTe QDs), as a probe was synthesized via a refluxing method [4]. Following, reverse microemulsion technique was applied to stabilize a thin silica shell on the surface of the QDs to get QDs@SiO2 nanocomposites. In the next step, MIPs embedded TGA-CdTe QDs were obtained using 3-aminopropyl triethoxysilane (as a monomer) and tetraethoxysilane (as a crosslinker) In the presence of PROP to produce QDs@SiO2@MIPs nanocomposites [5]. Finally, the obtained sensor was used for PROP sensing. At the optimized conditions, a linear dynamic range was obtained from 3.0 to 139 μmol L-1 PROP with a detection limit as 0.7 μmol L-1. The precision of the method for 30.0 and 70.0 μmol L-1 PROP was obtained as 6.5% and 4.8% (3 replicate detections), respectively. The QDs@SiO2@MIPs was successfully applied for the determination of PROP in human plasma samples. Selectivity of the PROP sensor was examined in the presence of some possible interfering substances in human plasma sample. As a result, the proposed PROP sensor exhibited good selectivity for determination of PROP. The proposed method was simple, selective, and cost-efficient for PROP measurement.