Proficient surface modification of CdSe quantum dots for highly luminescent and biocompatible probes for bioimaging: A comparative experimental investigation

Abstract The cytotoxicity of Cd based Quantum dots (QDs) is major concern that hinders their practical use in bioimaging. Therefore, the objective of first of its kind report is to overcome this hindrance where the comparative cytotoxicity study of poly CdSe, CdSe QDs, CdSe/ZnS QDs and CdSe QDs encapsulated by TEOS, polyvinylalcohal and polyethylene glycol being presented. All the QD were synthesized and encapsulated by wet chemical method and studied. Prepared QDs were monodispersed, spherical in shape and exhibited size range of 1.8–2.2 nm. Elemental analysis confirms the formation of CdSe QDs and other mentioned structures. Surface functional groups notify the biocompatibility of core-shell and encapsulated QDs with respect to poly and bare CdSe QDs. Cytotoxicity of QDs was analyzed using human embryonic kidney cell line. Encapsulated QDs were tested even at very high concentrations and for long incubation time of 24 h and even upto 72 h of incubation. Core-shell and encapsulated QDs acquire excellent monochromatic luminescence intensity and negligible cytotoxicity as compared to prepared poly CdSe and bare CdSe QDs thus can be used as luminescent probes for bioimaging.