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de Santana JF, Pilla V, Silva ACA, Dantas NO, Messias DN, Andrade AA. Optical characterization of core-shell quantum dots embedded in synthetic saliva: Temporal dynamics. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 151:208-12. [PMID: 26313857 DOI: 10.1016/j.jphotobiol.2015.08.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 07/19/2015] [Accepted: 08/14/2015] [Indexed: 10/23/2022]
Abstract
The present work reports the spectroscopic and thermo-optical properties of CdSe/ZnS and CdSe/CdS core-shell quantum dots (QDs) embedded in synthetic saliva. Spectroscopy studies were performed applying nonfunctionalized CdSe/ZnS QDs (3.4, 3.9 and 5.1 nm cores) and hydroxyl group-functionalized ultrasmall CdSe/CdS core-shell quantum dots (1.6 nm core) suspended in artificial saliva at different potential of hydrogen (pH) values. Saliva was chosen because it is important in a variety of functions such as protecting teeth through the buffering capacity of the formed biofilm, hydration, and dental remineralization. Thermo-optical characterizations using the thermal lens (TL) technique were performed in QD-biofluids for different QD sizes and pH values (3.9-8.3) of the synthetic oral fluids. Transient TL measurements were applied to determine the fluorescence quantum efficiency (η) in QD-biomaterial systems. High η value was obtained for ultrasmall CdSe/CdS QDs. Fluorescence spectral measurements of the biomaterials support the TL results. In addition, for nonfunctionalized (3.4 and 5.1 nm) and hydroxyl group-functionalized QDs, the temporal behavior of the fluorescence spectra was accomplished about approximately 1200 h at two different biofluid pH values (3.9 and 8.3). The temporal fluorescence intensity result is dependent on the pH of the saliva in which the QDs were embedded, QD functionalization and QD sizes. The time for an approximately 50% decrease in the peak intensity fluorescence of CdSe/ZnS QDs (3.4 nm core) and ultrasmall CdSe/CdS QDs is respectively 25 h and 312 h at pH 3.9 and 48 h and 360 h at pH 8.3.
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Affiliation(s)
- Juliana F de Santana
- Grupo de Propriedades Ópticas e Térmicas de Materiais (GPOTM), Instituto de Física, Universidade Federal de Uberlândia - UFU, Av. João Naves de Ávila 2121, Uberlândia, MG 38400-902, Brazil
| | - Viviane Pilla
- Grupo de Propriedades Ópticas e Térmicas de Materiais (GPOTM), Instituto de Física, Universidade Federal de Uberlândia - UFU, Av. João Naves de Ávila 2121, Uberlândia, MG 38400-902, Brazil.
| | - Anielle C A Silva
- Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia - UFU, Av. João Naves de Ávila 2121, Uberlândia, MG 38400-902, Brazil
| | - Noelio O Dantas
- Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia - UFU, Av. João Naves de Ávila 2121, Uberlândia, MG 38400-902, Brazil
| | - Djalmir N Messias
- Grupo de Propriedades Ópticas e Térmicas de Materiais (GPOTM), Instituto de Física, Universidade Federal de Uberlândia - UFU, Av. João Naves de Ávila 2121, Uberlândia, MG 38400-902, Brazil
| | - Acácio A Andrade
- Grupo de Propriedades Ópticas e Térmicas de Materiais (GPOTM), Instituto de Física, Universidade Federal de Uberlândia - UFU, Av. João Naves de Ávila 2121, Uberlândia, MG 38400-902, Brazil
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Zhao MX, Zeng EZ. Application of functional quantum dot nanoparticles as fluorescence probes in cell labeling and tumor diagnostic imaging. NANOSCALE RESEARCH LETTERS 2015; 10:171. [PMID: 25897311 PMCID: PMC4397224 DOI: 10.1186/s11671-015-0873-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 03/21/2015] [Indexed: 05/23/2023]
Abstract
Quantum dots (QDs) are a class of nanomaterials with good optical properties. Compared with organic dyes, QDs have unique photophysical properties: size-tunable light emission, improved signal brightness, resistance against photobleaching, and simultaneous excitation of multiple fluorescence colors. Possessing versatile surface chemistry and superior optical features, QDs are useful in a variety of in vitro and in vivo applications. When linked with targeting biomolecules, QDs can be used to target cell biomarkers because of high luminescence and stability. So QDs have the potential to become a novel class of fluorescent probes. This review outlines the basic properties of QDs, cell fluorescence labeling, and tumor diagnosis imaging and discusses the future directions of QD-focused bionanotechnology research in the life sciences.
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Affiliation(s)
- Mei-Xia Zhao
- Key Laboratory of Natural Medicine and Immune Engineering, Henan University, Kaifeng, 475004 China
| | - Er-Zao Zeng
- Key Laboratory of Natural Medicine and Immune Engineering, Henan University, Kaifeng, 475004 China
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High fluorescence quantum efficiency of CdSe/ZnS quantum dots embedded in GPTS/TEOS-derived organic/silica hybrid colloids. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2014.03.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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