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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Optical oxygen sensing by MPA-capped CdTe quantum dots immobilized in mesoporous silica

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Author(s):
Ravaro, Leandro P. [1, 2] ; Ford, Peter C. [1] ; de Camargo, Andrea S. S. [2]
Total Authors: 3
Affiliation:
[1] Univ Calif Santa Barbara, Dept Chem & Biochem, Santa Barbara, CA 93106 - USA
[2] Univ Sao Paulo, Sao Carlos Inst Phys, POB 369, BR-13560970 Sao Carlos, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Microporous and Mesoporous Materials; v. 303, AUG 15 2020.
Web of Science Citations: 0
Abstract

A novel nanocomposite luminescent material was prepared by taking advantage of the versatile wet impregnation method for the dispersion of CdTe quantum dots (QDs) into mesoporous silica host matrix and thus providing great interaction between oxygen and QDs, with potential application in an optical oxygen sensor. The optical/spectroscopic properties of the QDs suspended in aqueous media and incorporated in mesoporous silica were evaluated as a function of aging time, temperature variation and oxygen concentration. Luminescence quenching studies were carried out for both QDs suspended in solution and loaded into the silica matrix, in the presence of varying O-2 concentration. By Stern-Volmer plot analysis, obtained at different temperatures, it was possible to verify the existence of two types of emission quenching mechanisms for CdTe QDs. After aging for 120 days at room temperature, the QDs in colloidal suspension displayed a small red-shifted emission, which was interpreted as a decreased bandgap energy owing to the increase in the nanocrystal size. In contrast, the emission spectrum of CdTe QDs loaded into the mesoporous SiO2 matrix remained unchanged after aging for the same time at ambient temperature. The presented results will contribute to the discernment of oxygen quenching mechanisms and chemical stability of optical sensors based on CdTe QDs. (AU)

FAPESP's process: 13/24727-7 - New Optical Materials Based on Polynuclear Copper(I) Halide Cluster Complexes Immobilized in Solid Host Matrices
Grantee:Leandro Piaggi Ravaro
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass
Grantee:Edgar Dutra Zanotto
Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
FAPESP's process: 16/17495-0 - New photonic materials based on Cu(I) complexes, upconverting nanoparticles and quantum dots
Grantee:Leandro Piaggi Ravaro
Support Opportunities: Scholarships abroad - Research Internship - Post-doctor