title: Investigation of biocompatible and protein sensitive highly luminescent quantum dots/nanocrystals of CdSe, CdSe/ZnS and CdSe/CdS.
abstract: The size and shape dependent semiconductor quantum dots (0D nanoparticles) with color tunability demonstrating significant influence in a biological system and considered as ideal probes. Here, a non-coordinated colloidal approach was used for the synthesis of CdSe, CdSe/ZnS and CdSe/CdS core-shell quantum dots (QDs) of 3-4nm. The synthesized nanocrystals show a high crystallinity, examined by X-ray diffraction (XRD) and high-resolution electron microscopy (HRTEM). The core-shell semiconductor QDs exhibit stronger photoluminescence (PL) as compared to the core QDs. The strong PL with small full-width half maximum (FWHM) indicates that the prepared QDs have a nearly uniform size distribution and well dispersibility. The quantum yield (QY) of core-shell QDs increases due to the surface passivation. Further, the PL of BSA is quenched strongly by the presence of core-shell QDs and follows the well-known Stern-Volmer (S-V) relation, whereas the PL lifetime does not follow the S-V relation, demonstrating that the observed quenching is predominantly static in nature. Among CdSe core, CdSe/ZnS and CdSe/CdS core-shell QDs, the CdSe/ZnS QDs shows the least cytotoxicity and most biocompatibility. Thus, the prepared core-shell QDs are biocompatible and exhibit strong sensing ability.
authors.affiliation: Laser-Spectroscopy Laboratory, Department of Applied Physics, Delhi Technological University, Bawana Road, Delhi 110042, India.
authors.forename: R K
authors.initials: RK
authors.lastname: Ratnesh
authors.affiliation: Laser-Spectroscopy Laboratory, Department of Applied Physics, Delhi Technological University, Bawana Road, Delhi 110042, India. Electronic address: msmehata@gmail.com.
authors.forename: Mohan Singh
authors.initials: MS
authors.lastname: Mehata
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology; D019187:Cadmium Compounds / Q000737:chemistry* / Q000494:pharmacology; D002417:Cattle; D002460:Cell Line; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D007700:Kinetics; D049449:Luminescence; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D045663:Quantum Dots / Q000737:chemistry*; D011789:Quantum Theory; D018036:Selenium Compounds / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013440:Sulfides / Q000737:chemistry* / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction; D017967:Zinc Compounds / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D001672:Biocompatible Materials; D019187:Cadmium Compounds; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C034939:cadmium sulfide; D014867:Water; D012710:Serum Albumin, Bovine; C058667:cadmium selenide; C031238:zinc sulfide
keywords: An optical sensor; Core-shell quantum dots; Cytotoxicity; Lifetime; Optical properties