Conjugates of semiconductor quantum dots (QDs) and organic dyes have been receiving attention as fluorescence biological sensing materials. In designing such sensors, a most important parameter is the number of organic-dye molecules that conjugate to a QD. If a precise separation method was developed, it might be possible to control conjugation without knowing the exact number of conjugated dye molecules per QD. In this study, the difference in linear velocities in a gel filtration column between CdSe/ZnS QDs and 5-(and 6)-carboxynaphthofluorescein succinimidyl ester is used. The velocities differ because the hydrophilicity of CdSe/ZnS QDs is much higher than that of the organic dye; hence, CdSe/ZnS-organic-dye conjugation can be controlled by changing the fraction number. Furthermore, the concentrations of CdSe/ZnS QDs and organic dye in fractionated solutions can be determined by measuring fluorescence spectra, and we demonstrate a fluorescence-type pH sensor based on the conjugate, which has a pH-sensitivity range from 7.5 - 9.5.
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http://dx.doi.org/10.2116/analsci.32.529 | DOI Listing |
ChemMedChem
January 2025
Shanghai University, Institute of Nanochemistry and Nanobiology, No.99 Shangda Rd. Rm201, Bldg. E, 200444, Shanghai, CHINA.
As a newly emerging technology, conformational engineering (CE) has been gradually displaying the power of producing protein-like nanoparticles (NPs) by tuning flexible protein fragments into their original native conformation on NPs. But apparently, not all types of NPs can serve as scaffolds for CE. To expedite the CE technology on a broader variety of NPs, the essential characteristic of NPs as scaffolds for CE needs to be identified.
View Article and Find Full Text PDFRSC Med Chem
November 2024
Department of Chemistry, Christ University Hosur Road Bangalore Karnataka 560029 India
Colloids Surf B Biointerfaces
February 2025
College of Marine Life Science, Sanya Oceanographic Institute, Ocean University of China, Qingdao/ Sanya, 266000, China. Electronic address:
Diatoms have developed unique micro- and nanostructures and photonic crystal properties during billions of years of life evolution. In this study, a fluorescence sensor substrate (QD-Diatom) was prepared by biofabrication, and CdSe/ZnS quantum dots (QDs) were immobilized on the surface of diatom biosilica. The concentration of CdSe/ZnS QDs of 7.
View Article and Find Full Text PDFThe photoluminescence properties of quantum dots (QDs) are often enhanced by eliminating surface trap states through chemical methods. Alternatively, a physical approach is presented here for improving photoluminescence purity in QDs by employing frequency-specific plasmon resonance coupling. Emitter-bound plasmonic hybrids are designed by electrostatically binding negatively charged QDs in water to positively charged gold nanoparticles having a thin polymer coating.
View Article and Find Full Text PDFAnal Chim Acta
December 2024
College of Information Science and Engineering, Northeastern University, Shenyang, 110819, China; Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology, Qinhuangdao, 066004, China; State Key Laboratory of Synthetical Automation for Process Industries, Shenyang, 110819, China.
Background: Copper ion (Cu), a crucial heavy metal ion, is closely associated with human health and the ecological environment. Imbalances in Cu can result in health issues for humans and damage to the ecosystem. Therefore, it is essential to detect Cu in the environment.
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