CdSe/CdS Core/Shell Quantum Dots Synthesized with Water Soluble Polymer for Potential Biosensor Applications

Quantum dots (QDs) are very promising advanced materials due to their nanoscale dimensions and properties of quantum confinement. Among the most promising applications of QDs, the use as biomaterials is highlighted, especially as optical biosensors and biomarkers. In this work CdSe-CdS core-shell nanoparticles were obtained through colloidal aqueous route at room temperature. The biocompatible polymer poly (vinyl alcohol) modified with carboxyl groups (PVA-COOH) was used as a stabilizing agent. The effect of growing CdS shell on the quantum properties and dimensions of CdSe nanoparticles (core-shell structure) was studied by UV-vis spectroscopy, photoluminescence (PL) and transmission electron microscopy (TEM). The results showed the influence of the growth of the CdS shell layers in the optical properties of quantum dots. Based on the results it can be stated that conjugated systems of CdS/CdSe-PVA-COOH were obtained and exhibited enhanced photoluminescent behavior, an essential property to use this system in biosensing devices.