Determination of Aspirin Using Functionalized Cadmium-Tellurium Quantum Dots as a Fluorescence Probe

A simple and sensitive method is reported for the synthesis of photoluminescent semiconductor CdTe quantum dots. The CdTe quantum dots were synthesized by using mercaptosuccinic acid for protection in the aqueous phase and used for the determination of aspirin by a quenching reaction. By comparison with thioglycolic acid stabilized CdTe quantum dots, the mercaptosuccinic acid shortened the reaction time. Transmission electron microscopy was used to characterize the CdTe quantum dots; their size was approximately 5.0 nm. The interaction between the CdTe quantum dots and aspirin was characterized by fluorescence and absorption spectroscopy. The optimum pH for measurements was 8.0. Under the optimized conditions, the fluorescence intensity of the CdTe quantum dots had a linear relationship with the concentration of aspirin between 1.7 and 56 µmol/L and the quenching reaction was shown to have a static mechanism. As the concentration of aspirin increased, the fluorescence quenching of mercaptosuccinic acid stabilized CdTe quantum dots increased. This method was successfully used for the determination of aspirin in tablets.