title: Interaction of glucose-derived carbon quantum dots with silver and gold nanoparticles and its application for the fluorescence detection of 6-thioguanine.
abstract: The interaction of glucose-derived carbon quantum dots (CQDs) with silver (Ag) and gold (Au) nanoparticles (NPs) was explored by fluorescence spectroscopy. Both metal NPs cause an efficient quenching of CQD fluorescence, which is likely due to the energy transfer process between CQDs as donors and metal NPs as acceptors. The Stern-Volmer plots were evaluated and corresponding quenching constants were found to be 1.9 × 1010and 2.2 × 108M-1for AgNPs and AuNPs, respectively. The analytical applicability of these systems was demonstrated for turn-on fluorescence detection of the anti-cancer drug, 6-thioguanine. Because the CQD-AgNP system had much higher sensitivity than the CQD-AuNP system, we used it as a selective fluorescence probe in a turn-on assay of 6-thioguanine. Under optimum conditions, the calibration graph was linear from 0.03 to 1.0 μM with a detection limit of 0.01 μM. The developed method was applied to the analysis of human plasma samples with satisfactory results.
authors.affiliation: Department of Analytical Chemistry, University of Tabriz, Tabriz, East Azerbaijan, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Amjadi
authors.affiliation: Department of Analytical Chemistry, University of Tabriz, Tabriz, East Azerbaijan, Iran.
authors.forename: Roghayeh
authors.initials: R
authors.lastname: Shokri
authors.affiliation: Department of Analytical Chemistry, University of Tabriz, Tabriz, East Azerbaijan, Iran.
authors.forename: Tooba
authors.initials: T
authors.lastname: Hallaj
mesh_terms: D002244:Carbon / Q000737:chemistry*; D005453:Fluorescence; D005947:Glucose / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D045663:Quantum Dots; D012834:Silver / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013499:Surface Properties; D013866:Thioguanine / Q000032:analysis*
chemical_list: D012834:Silver; D002244:Carbon; D006046:Gold; D013866:Thioguanine; D005947:Glucose
keywords: 6-thioguanine; carbon quantum dots; fluorescence quenching; gold nanoparticles; silver nanoparticles