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Goryacheva OA, Wegner KD, Sobolev AM, Häusler I, Gaponik N, Goryacheva IY, Resch-Genger U. Influence of particle architecture on the photoluminescence properties of silica-coated CdSe core/shell quantum dots. Anal Bioanal Chem 2022; 414:4427-4439. [PMID: 35303136 DOI: 10.1007/s00216-022-04005-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/28/2022] [Accepted: 03/02/2022] [Indexed: 12/25/2022]
Abstract
Light-emitting nanoparticles like semiconductor nanocrystals (termed quantum dots, QDs) are promising candidates for biosensing and bioimaging applications based on their bright and stable photoluminescent properties. As high-quality QDs are often synthesized in organic solvents, strategies needed to be developed to render them water-dispersible without affecting their optical properties and prevent changes in postmodification steps like the biofunctionalization with antibodies or DNA. Despite a large number of studies on suitable surface modification procedures, the preparation of water-soluble QDs for nanobiotechnology applications still presents a challenge. To highlight the advantages of surface silanization, we systematically explored the influence of the core/multishell architecture of CdSe/CdS/ZnS QDs and the silanization conditions on the optical properties of the resulting silanized QDs. Our results show that the optical properties of silica-coated CdSe/CdS/ZnS QDs are best preserved in the presence of a thick CdS (6 monolayers (ML)) intermediate shell, providing a high photoluminescence quantum yield (PL QY), and a relatively thick ZnS (4.5 ML) external shell, effectively shielding the QDs from the chemical changes during silica coating. In addition to the QD core/shell architecture, other critical parameters of the silica-coating process, that can have an influence on the optical properties of the QD, include the choice of the surfactant and its concentration used for silica coating. The highest PL QY of about 46% was obtained by a microemulsion silica-coating procedure with the surfactant Brij L4, making these water-dispersible QDs to well-suited optical reporters in future applications like fluorescence immunoassays, biomedicine, and bioimaging.
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Affiliation(s)
- Olga A Goryacheva
- Department of General and Inorganic Chemistry, Chemistry Institute, Saratov State University, Astrakhanskaya 83, 410012, Saratov, Russia. .,Physical Chemistry, Technische Universität Dresden, Zellescher Weg 19, 01062, Dresden, Germany.
| | - K David Wegner
- Division Biophotonics, Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Straße 11, 12489, Berlin, Germany
| | - Aleksandr M Sobolev
- Department of General and Inorganic Chemistry, Chemistry Institute, Saratov State University, Astrakhanskaya 83, 410012, Saratov, Russia.,Division Biophotonics, Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Straße 11, 12489, Berlin, Germany
| | - Ines Häusler
- AG Strukturforschung/Elektronenmikroskopie, Institut Für Physik, Humboldt-Universität Zu Berlin, Newtonstraße 15, 12489, Berlin, Germany
| | - Nikolai Gaponik
- Physical Chemistry, Technische Universität Dresden, Zellescher Weg 19, 01062, Dresden, Germany
| | - Irina Y Goryacheva
- Department of General and Inorganic Chemistry, Chemistry Institute, Saratov State University, Astrakhanskaya 83, 410012, Saratov, Russia
| | - Ute Resch-Genger
- Division Biophotonics, Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Straße 11, 12489, Berlin, Germany.
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Zhou S, Xie B, Yang X, Zhang X, Luo X. Superior hydrophobic silica-coated quantum dot for stable optical performance in humid environments. NANOTECHNOLOGY 2022; 33:195202. [PMID: 35086083 DOI: 10.1088/1361-6528/ac4f81] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
Quantum dot (QD) features many exceptional optical performances but is also vulnerable to moisture which results in structural damage and luminescent decrease. This work provided and fabricated a novel superior hydrophobic methylated core/shell silica-coated QD (MSQ) for high water stability. QD was coated with a silica shell and then surface-methylated by trimethyl silane. Mercaptopropyl trimethoxy silane, tetraethyl orthosilicate, and ethoxy trimethyl silane were utilized as the ligand exchanger, the raw material of silica, and the surface modification, respectively. Characterization results illustrated the core/shell structure of MSQ. In addition, its water contact angle was up to 159.6°. QD-, silica-coated QD(SQ)-, and MSQ-silicone were made and displayed similar absorption, emission, and excitation spectra but different water stabilities. The photoluminescence intensity and photoluminescence quantum yield of MSQ-silicone hardly changed during 15 d of water immersion, in contrast to the dramatical decrease of other two kinds of composite silicone. Specifically, the photoluminescence quantum yield decreases of MSQ-, SQ-, and QD-silicone were 1%, 40%, and 43%, respectively. Therefore, MSQ had a much better water stability. The superior hydrophobic methylated silica-coated QD has a great potential to realize the long-term working stability in a humid environment and the wider application in diverse fields.
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Affiliation(s)
- Shuling Zhou
- School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Bin Xie
- School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Xuan Yang
- School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Xinfeng Zhang
- School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Xiaobing Luo
- School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
- Wuhan National Laboratory for Optoelectronics, Wuhan 430074, People's Republic of China
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