Functionalized InP/ZnS Quantum Dots Synthesis for Applications in Drug Delivery Systems

Abstract Quantum dots are semiconductors with sizes less than their excitonic diameter, exhibiting quantum confinement effect and unique optical properties, including size adjustable fluorescent. Optical properties of quantum dots along with high surface to volume ratio and surface chemistry of quantum dots make them appealing for functionalization with variety of biomolecules, giving them applicability in bio-imaging and drug delivery. So they can be used for simultaneous diagnosis and treatment of cancer cells. In this study, core/shell InP/ZnS quantum dots were synthesized via hot injection colloidal method. Optical properties of synthesized quantum dots were investigated. TEM image of quantum dots showed approximately average size of 10 nm and spherical morphology of quantum dots. After transferring the quantum dots from organic to aqueous media via ligand exchange process, quantum dots were further functionalized with folic acid. Cytotoxicity of bare and functionalized InP/ZnS quantum dots on OVCAR-3 cell lines were investigated using MTT assay at different concentrations. The results indicated low toxicity of bare and functionalized InP/ZnS quantum dots. Cellular uptake of the functionalized and bare quantum dots were investigated on OVCAR-3 and A549 cell lines using FACS flow cytometry and results showed the enhancement of functionalized quantum dots internalization into folic acid receptor positive cell lines in comparison with bare quantum dots. Accordingly the functionalized InP/ZnS quantum dots are proper candidates for simultaneous bio-imaging and drug delivery.