scholarly journals Potassium-Induced Emission Enhancement of Bovine Serum Albumin-Stabilized Red-Emitting Au Nanoclusters: Mechanism and Application to Blood Plasma

2021 ◽  
Author(s):  
Achmad Hidayat ◽  
Nicole Wawrzyniak ◽  
Adam Domanski ◽  
Yutaka Shibata ◽  
Akiko Hori ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Blood Plasma ◽  
Emission Intensity ◽  
Bovine Serum ◽  
Gold Nanoclusters ◽  
Normal Function ◽  
Quantum Yields ◽  
Physiological Concentration ◽  
Emission Enhancement

Abstract Aggregation-induced emission (AIE) enhancement is attractive for bioimaging as it offers higher quantum yields (QYs) from fluorophores via modulation of their immediate environment. Fluorophores with high QYs are essential probes for investigating the spatiotemporal distribution of physiologically important metal ions such sodium and potassium. Potassium ions are vital for normal function of living organisms. The research reported here evaluates the emission intensity of the bovine serum albumin-stabilized red-emitting gold nanoclusters (BSA-rAuNCs) upon uptake of K+. The integrated sphere method was used to determine the absolute QYs and a custom-built fluorescence setup recorded the emission spectra of BSA-rAuNCs. Enhancement of emission intensity was observed upon increasing K+ concentration, within the physiological concentration range of 0 - 150 mM. The emission enhancement was correlated with the particle size and charge analysis. Aggregation of BSA-rAuNCs was found to be responsible for the observed emission enhancement. The QY of BSA-rAuNCs in bovine blood plasma was found to be four times lower than corresponding QY in water.

scholarly journals Identifying Reducing and Capping Sites of Protein-Encapsulated Gold Nanoclusters

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1630 ◽  
Author(s):  
Yu-Chen Hsu ◽  
Mei-Jou Hung ◽  
Yi-An Chen ◽  
Tsu-Fan Wang ◽  
Ying-Ru Ou ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Conformational Changes ◽  
Local Structure ◽  
Bovine Serum ◽  
Gold Nanoclusters ◽  
Cysteic Acid ◽  
Subsequent Growth ◽  
The Core

The reducing and capping sites along with their local structure impact photo properties of the red bovine serum albumin-capped Au nanocluster (BSA-AuNC), however, they are hard to identify. We developped a workflow and relevant techniques using mass spectrometry (MS) to identify the reducing and capping sites of BSA-AuNCs involved in their formation and fluorescence. Digestion without disulfide cleavages yielded an Au core fraction exhibiting red fluorescence and [AunSm] ion signals and a non-core fraction exhibiting neither of them. The core fraction was identified to mainly be comprised of peptides containing cysteine residues. The fluorescence and [AunSm] signals were quenched by tris(2-carboxyethyl)phosphine, confirming that disulfide groups were required for nanocluster stabilization and fluorescence. By MS sequencing, the disulfide pairs, C75–C91/C90–C101 in domain IA, C315–C360/C359–C368 in domain IIB, and C513–C558/C557–C566 in domain IIIB, were identified to be main capping sites of red AuNCs. Peptides containing oxidized cysteines (sulfinic or cysteic acid) were identified as reducing sites mainly in the non-core fraction, suggesting that disulfide cleavages by oxidization and conformational changes contributed to the subsequent growth of nanoclusters at nearby intact disulfide pairs. This is the first report on precise identification of the reducing and capping sites of BSA-AuNCs.

scholarly journals A Turn-On Fluorescent Sensor for Glutathione Based on Bovine Serum Albumin-Stabilized Gold Nanoclusters

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Yan Qiu ◽  
Jianlin Huang ◽  
Li Jia
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Fluorescent Sensor ◽  
Gold Nanoclusters ◽  
Copper Ion ◽  
Fluorescence Sensor ◽  
Gold Nanocluster ◽  
Experimental Conditions ◽  
Bovine Serum Albumin Molecule

A fluorescence sensor for the detection of glutathione based on the fluorescence recovering of the bovine serum albumin-stabilized gold nanoclusters is reported. This study indicates that glutathione restores the copper-ion-quenched fluorescence by coordinating the bound copper ion in the bovine serum albumin molecule used for stabilizing the gold nanocluster through its sulfydryl. Under the experimental conditions, the fluorescence response showed a linear relationship with the concentration of glutathione over the range from 10 µM to 400 µM. The fluorescence sensor successfully detected glutathione in commercial drug products.

scholarly journals The Synthesis of Wavelength-Controlled CdTe/Hydroxyapatite Composites and Their Fluorescence Enhancement by Bovine Serum Albumin

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Li Jin ◽  
Lihua Na ◽  
Xueling Cao ◽  
Fangli Zhong ◽  
Jianpo Zhang
Keyword(s):  
Quantum Dots ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Emission Intensity ◽  
Bovine Serum ◽  
Fluorescence Spectra ◽  
Fluorescence Emission ◽  
Biochemical Processes ◽  
Before And After ◽  
A Site

For the last ten years, quantum dots modified by biological materials have made it possible to study biochemical processes by means of biomedical imaging. This thesis introduced how the fluorescence CdTe quantum dots/hydroxyapatite composites were synthesized and how their structure, morphology, and fluorescence property were characterized by using TEM, XRD, EDS, UV-vis absorption spectra, and fluorescence spectra. The fluorescence spectra indicated the superb photometric characteristics of CdTe/HA composites. We also found that refluxing temperature and time had prominent effects on fluorescence wavelength and intensity of CdTe/HA composites, so the fluorescence emission wavelength of CdTe/HA composites could be controlled. In addition, the effect of BSA on the fluorescence properties of CdTe/HA composites was studied. The fluorescent emission intensity of CdTe/HA composites was enhanced directly with increasing concentrations of BSA; meanwhile, the fluorescence emission intensity of BSA dramatically decreased, which indicated that a Förster nonradiative energy transfer process occurred through the formation of chemical bonds between BSA and CdTe/HA composites. And the two-dimensional correlation (2D COS) was used to analyze the BSA solution before and after the reaction, which indicated that CdTe/HA composites have bound to a site at the surface of the molecule in the first subdomain IA. We also found that there was a linear relationship between the fluorescence intensity enhancement (F/F0) of CdTe/HA composites and the concentration of the bovine serum albumin, which might become a method for quantitative analysis of BSA in a real sample.

Ratiometric fluorescence determination of alkaline phosphatase activity based on dual emission of bovine serum albumin-stabilized gold nanoclusters and the inner filter effect

The Analyst ◽  
2021 ◽  
Author(s):  
Li Pu ◽  
Mengfan Xia ◽  
Pengyue Sun ◽  
Yaodong Zhang
Keyword(s):  
Alkaline Phosphatase ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Gold Nanoclusters ◽  
Inner Filter Effect ◽  
Ratiometric Fluorescence ◽  
Dual Emission ◽  
Filter Effect

Ratiometric fluorescence assay of alkaline phosphatase based on dual emission of bovine serum albumin-templated gold nanoclusters and inner filter effect.

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