Fluorescence enhancement of CdTe MPA-capped quantum dots by glutathione for hydrogen peroxide determination.
The manipulation of the surface chemistry of semiconductor nanocrystals has been exploited to implement distinct sensing strategies in many analytical applications. In this work, reduced glutathione (GSH) was added at reaction time, as an electron-donor ligand, to markedly increase the quantum yield and the emission efficiency of MPA-capped CdTe quantum dots. The developed approach was employed in the implementation of an automated flow methodology for hydrogen peroxide determination, as this can oxidize GSH preventing its surface passivating effect and producing a manifest fluorescence quenching. After optimization, linear working calibration curve for hydrogen peroxide concentrations between 0.0025% and 0.040% were obtained (n=6), with a correlation coefﬁcient of 0.9975. The detection limit was approximately 0.0012%. The developed approach was employed in the determination of H₂O₂ in contact lens preservation solutions and the obtained results complied with those furnished by the reference method, with relative deviations comprised between -1.18 and 4.81%.
Requimte, Department of Chemical Sciences, Laboratory of Applied Chemistry, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira no 228, 4050-313 Porto, Portugal.
S Sofia M
SS
Rodrigues
Requimte, Department of Chemical Sciences, Laboratory of Applied Chemistry, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira no 228, 4050-313 Porto, Portugal. Electronic address: dsmribeiro@gmail.com.
David S M
DS
Ribeiro
Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences, University of Jaén, Campus las Lagunillas, E-23071 Jaén, Spain.
L
L
Molina-Garcia
Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences, University of Jaén, Campus las Lagunillas, E-23071 Jaén, Spain.
A
A
Ruiz Medina
Requimte, Department of Chemical Sciences, Laboratory of Applied Chemistry, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira no 228, 4050-313 Porto, Portugal.
João A V
JA
Prior
Requimte, Department of Chemical Sciences, Laboratory of Applied Chemistry, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira no 228, 4050-313 Porto, Portugal.
João L M
JL
Santos
D019187:Cadmium Compounds / Q000737:chemistry*; D005978:Glutathione / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis*; D045663:Quantum Dots / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013691:Tellurium / Q000737:chemistry*
D019187:Cadmium Compounds; D006861:Hydrogen Peroxide; D005978:Glutathione; D013691:Tellurium; C028337:cadmium telluride
CdTe quantum dots; Flow analysis.; Fluorescence enhancing; Glutathione; Surface passivation