The photoluminescence from water-soluble gold nanoparticles, each composed of a 5.1 nm gold core and a bovine serum albumin (BSA)-protected layer, has been observed. The maximal excitation and the maximal emission wavelength are at 320 and 404 nm, respectively. The photoluminescence quantum yield is estimated as 0.053+/-0.0070, at room temperature. The mechanism of the luminescence is hypothesized to be associated with interband transitions between the filled 5d(10) band and 6(sp)(1) conduction band. The photoluminescence is sensitive to pH, organic solvents and metal ions. These observations suggest that this nanoparticles are a viable alternative to organic fluorophores or semiconductor nanoparticles for biological labeling and imaging.
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http://dx.doi.org/10.1016/j.saa.2007.05.022 | DOI Listing |
J Fluoresc
January 2025
Electrical Engineering, Indian Institute of Technology, Gandhinagar, Gujarat, India.
Graphene quantum dots (GQDs) are highly valued for their chemical stability, tunable size, and biocompatibility. Utilizing green chemistry, a microwave-assisted synthesis method was employed to produce water-soluble GQDs from Mangifera Indica leaf extract. This approach is efficient, cost-effective, and environmentally friendly, offering reduced reaction times, energy consumption, and uniform particle sizes, and has proven advantageous over other methods.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan, 250061, China.
The absence of the enhancement of fluorescence in carbon dots (CDs) through doping with transition metal atoms (TMAs) hinders the advancement of multi-modal bio-imaging CDs with high photoluminescence quantum yield (PLQY). Herein, Mn-atomically-doped R-CDs (R-Mn-CDs) with a high PLQY of 41.3% in water is presented, enabling efficient in vivo dual-mode fluorescence/magnetic resonance (MR) imaging.
View Article and Find Full Text PDFMikrochim Acta
December 2024
Key Laboratory of Chemistry and Engineering of Forest Products, State Ethnic Affairs Commission, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products/Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products, Guangxi Colleges Universities Key Laboratory of Optic-Electric Chemo/Biosensing and Molecular Recognition, Guangxi Minzu University, Nanning, 530006, China.
A dual supersaturation recrystallization method was employed to synthesize water-stable, highly sensitive cesium-lead halide perovskite nanocrystals (CsPbBr PNCs). The PNCs exhibited excellent water stability, a significant photoluminescence quantum efficiency of 83.03%, along with a narrow full width at half maximum (FWHM) of 20 nm.
View Article and Find Full Text PDFLuminescence
December 2024
School of Biotechnology, KIIT University, Bhubaneswar, Odisha, India.
This study presents a mild, one-pot synthetic approach for the synthesis of multicolor, water soluble, photo luminescent CdS and CdSe quantum dots (QDs). To achieve this goal, cyclic peptides containing cysteine residues are rationally designed and synthesized. Among the peptides tested, those containing two cysteine residues exhibit superior stabilizing properties, ensuring the solubility and long-term stability of the QDs in aqueous solutions for several months.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
February 2025
Department of Chemistry, Istanbul Technical University, Maslak 34469, Istanbul, Türkiye; Department of Polymer Science and Technology, Istanbul Technical University, Maslak 34469, Istanbul, Türkiye. Electronic address:
Water soluble Zn based quantum dots (QDs) are of interest due to their biocompatibility and less toxic features. They have been frequently used in studies related to biotechnology, especially in agriculture studies. However, to control the optical properties of Zn based QDs has still been a challenge.
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