title: Interaction of CdTe quantum dots with 2,2-diphenyl-1-picrylhydrazyl free radical: a spectroscopic, fluorimetric and kinetic study.
abstract: The interaction of 2,2-diphenyl-1-picrylhydrazyl (DPPH(·) free radical with thiol-capped CdTe quantum dots (QDs) has been studied by UV-vis spectroscopy, steady state and time resolved fluorescence measurements. Addition of DPPH(·) radical to CdTe QDs resulted in fluorescence quenching. The interaction occurs through static quenching as this was confirmed by fluorescence lifetime measurements. Time course absorption studies indicates that DPPH(·) may be reduced by interaction with QDs to the substituted hydrazine form (2,2-diphenyl-1-picrylhydrazine) DPPH-H. The mechanism of fluorescence quenching of CdTe QDs by DPPH(·) is proposed.
authors: Department of Chemistry, Rhodes University, Grahamstown, South Africa.
authors: Oluwasesan
authors: O
authors: Adegoke
authors: Wadzanai
authors: W
authors: Chidawanyika
authors: Tebello
authors: T
authors: Nyokong
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry*; D019187:Cadmium Compounds / Q000737:chemistry*; D005453:Fluorescence; D005470:Fluorometry; D005609:Free Radicals / Q000737:chemistry; D007700:Kinetics; D010851:Picrates / Q000737:chemistry*; D045663:Quantum Dots; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013691:Tellurium / Q000737:chemistry*
chemical_list: D001713:Biphenyl Compounds; D019187:Cadmium Compounds; D005609:Free Radicals; D010851:Picrates; C004931:1,1-diphenyl-2-picrylhydrazyl; D013691:Tellurium; C028337:cadmium telluride