摘要:
The protamine capped gold nanoclusters (AuNCs@PRT) were synthesized by an one-pot approach, and utilized as a nanoprobe for highly sensitive and selective assay of U(VI) ions. The method is based on the aggregation induced fluorescent quenching of AuNCs@PRT by U(VI) ions. Under optimum conditions, the decrease of fluorescence intensity displayed a good linear correlation with the concentration of U(VI) ions ranging from 20.4nM to 9.74muM, with a detection limit of 6.1nM. The relative standard deviations were 3.86%, 1.41% and 1.71% via 11 detections at concentrations of 40nM, 0.40muM and 4.0muM of U(VI), respectively. The quenching mechanism was demonstrated to be due to the binding of U(VI) towards PRT to cause the aggregation of AuNCs@PRT rather than metal-metal interaction. The results suggest the potential application of this approach for monitoring the level of U(VI) in environmental samples.
通讯机构:
[Wang, YS; Li, L] U;Univ South China, Coll Publ Hlth, Hengyang 421001, Peoples R China.
关键词:
Electrostatic interactions;High quantum efficiency;Human urine samples;Hydrogen bonding;Hydrophobic interaction;Nanoprobe;Photoluminescence quenching;Resonance energy transfer
摘要:
This work describes a method for the determination of 1-hydroxypyrene (OH-Py) via aggregation-induced quenching of the emission of protamine-coated gold nanoclusters using 9-hydroxyphenanthrene (OH-Phe) as a sensitizer to boost the emission efficiency of nanoprobe. Under optimum conditions, the drop in fluorescence intensity at excitation/emission wavelengths of 300/596 nm is proportional to the concentrations of OH-Py in the range from 1.0 to 65 nM. The relative standard deviations are 4.2, 2.4 and 1.9% (for n = 11) at concentration levels of 8.0, 32 and 48 nM of OH-Py, respectively. The detection limit is 0.3 nM which is much lower than that of some previously reported methods. The recoveries from urine samples spiked with OH-Py ranged between 94.4 and 98.8%. Graphical abstract 1-Hydroxypyrene (OH-Py) can trigger the aggregation of protamine-gold nanoclusters (PRT-AuNCs), resulting in the emission quenching of PRT-AuNCs. 9-Hydroxyphenanthrene (OH-Phe) can boost the emission efficiency of nanoprobe. Thereby, a highly sensitive assay of OH-Py was established.
摘要:
The authors report on a one-pot approach for synthesizing highly fluorescent protamine-stabilized gold nanoclusters. These are shown to be a viable nanoprobe for selective and sensitive fluorometric determination of lead(II) via quenching of fluorescence via Pb(II)-Au(I) interaction. Under optimized conditions, fluorescence measured at excitation/emission peaks of 300/599 nm drops in the 80 nM-15 muM lead(II) concentration range. The detection limit is 24 nM, and relative standard deviations (for n = 11) at concentrations of 0.10, 4.0 and 15 muM are 1.6, 2.5 and 1.9%, respectively. The relative recoveries of added lead(II) in the water samples ranged from 97.9 +/- 2.29% to 101.2 +/- 1.83%. Graphical abstract Lead(II) ions are found to be able to selectively and sensitively quench the fluorescence of the protamine-gold nanoclusters (PRT-AuNCs). Thereby, an inexpensive, selective and sensitive lead(II) assay was established.
期刊:
Analytical and Bioanalytical Chemistry,2018年410(28):7385-7394 ISSN:1618-2642
通讯作者:
Wang, Yong-Sheng
作者机构:
[Zhou, Bin; Chen, Si-Han; Xue, Jin-Hua; Huang, Yan-Qin; Fu, Sha; Wang, Yong-Sheng] Univ South China, Coll Publ Hlth, West Changsheng Rd 28, Hengyang 421001, Hunan, Peoples R China.;[Xiao, Xi-Lin] Univ South China, Coll Chem & Chem Engn, Hengyang 421001, Hunan, Peoples R China.
通讯机构:
[Wang, Yong-Sheng] U;Univ South China, Coll Publ Hlth, West Changsheng Rd 28, Hengyang 421001, Hunan, Peoples R China.
关键词:
Colorimetric sensing;Hg2+-Au0/Au+ interaction;Mercury;Partly oxidized Au species;Peroxidase-like activity;Protamine-gold nanoclusters
摘要:
We certify that protamine-gold nanoclusters (PRT-AuNCs) synthesized by one-pot method exhibit peroxidase-like activity. The catalytic activity of PRT-AuNCs followed typical Michaelis–Menten kinetics and exhibited higher affinity to 3,3′,5,5′-tetramethylbenzidine (TMB) as the substrate compared to that of natural horseradish peroxidase. Meanwhile, we found that Hg(II) could dramatically and selectively enhance the peroxidase-like activity of PRT-AuNCs, and the enhanced mechanism by Hg(II) was demonstrated to be generation of the cationic Au species and the partly oxidized Au species (Auδ+) by Hg2+–Au0/Au+ interaction. Based on this finding, quantitative determinations of Hg(II) via visual observation and absorption spectra were achieved. The proposed strategy displays high selectivity that arises from the strong aurophilic interaction of mercury towards gold. Moreover, the developed method is highly sensitive with a wide linear range and low detection limit of 1.16 nM. This strategy is not only helpful to develop effective nanomaterials-based artificial enzyme mimics but also irradiative to discover new applications of artificial mimic enzymes in bio-detection, medical diagnostics, and biotechnology. Protamine-gold nanoclusters (PRT-AuNCs) synthesized by one-pot method exhibit peroxidase-like activity. Hg(II) can stimulate the peroxidase-like activity of PRT-AuNCs selectively, enhancing their ability to catalyze the chromogenic reaction of TMB by H2O2
摘要:
The coordination reaction of thorium (IV) with a ditopic bidentate ligand to form supramolecular polymer was studied by resonance light scattering (RLS) spectra, second-order scattering (SOS) spectra and frequency-doubling scattering (FDS) spectra, respectively. The ditopic bidentate ligand is isophthalaldehyde-tetrapyrrole (IPTP). It was synthesized through a condensation reaction of isophthalaldehyde with pyrrole. The formation of supramolecular polymer results in remarkable intensity enhancements of the three light scattering signals. The maximum scattering wavelengths of RLS, FDS and SOS were 290, 568 and 340 nm, respectively. The reaction was used to establish new light scattering methods for the determination of thorium (IV) by using IPTP as probe. Under optimum conditions, the intensity enhancements of RLS, SOS and FDS were directly proportional to the concentration of thorium (IV) in the ranges of 0.01 to 1.2 mu g mL(-1), 0.05 to 1.2 mu g mL(-1) and 0.05 to 1.2 mu g mL(-1), respectively. The detection limits were 0.003 mu g mL(-1), 0.012 mu g mL(-1) and 0.021 mu g mL(-1), respectively. The methods were suitable for analyzing thorium (IV) in actual samples. The results show acceptable recoveries and precision compared with a reference method. (C) 2017 Elsevier B.V. All rights reserved.
期刊:
Sensors and Actuators B-Chemical,2016年235:507-514 ISSN:0925-4005
通讯作者:
Wang, Yong-Sheng
作者机构:
[Zhou, Bin; Yin, Ji-Cheng; Chen, Si-Han; Tang, Xian; Xue, Jin-Hua; Zhu, Yu-Feng; Huang, Yan-Qin; Wang, Yong-Sheng; Wang, Xiao-Feng] Univ South China, Coll Publ Hlth, Hengyang 421001, Peoples R China.;[Yin, Ji-Cheng] Ctr Dis Control & Prevent Zibo City Shandong Prov, Zibo 255000, Peoples R China.;[Xiao, Xi-Lin] Univ South China, Coll Chem & Chem Engn, Hengyang 421001, Peoples R China.
通讯机构:
[Wang, Yong-Sheng] U;Univ South China, Coll Publ Hlth, Hengyang 421001, Peoples R China.
关键词:
Wireless magnetoelastic sensor;Mercury(II) specific aptamer probe;Graphene oxide;Streptavidin;Gold nanoparticles
摘要:
A novel wireless magnetoelastic sensor (WMS) strategy for Hg2+ assay was proposed using a specific aptamer probe and graphene oxide (GO) as an adsorbent. The introduction of Hg2+ results in the release of CDNA-biotin. This one can be adsorbed to the surface of GO that was immobilized on the WMS along with a decrease of the resonance frequency of the sensor. A biotin-streptavidin (SA)-gold nanoparticles( AuNPs) system designed in this work was used for amplifying response signal of the sensor. The signal intensity linearly correlated with Hg2+ concentration ranging from 2.80 to 88.9 nM with a detection limit of 0.885 nM. This WMS has additional advantages of being less time-consuming, low cost and remote query, and can be employed for the real-time and in situ detection of Hg2+ in real samples. The mechanism for structure switching and signal amplification was also studied by transmission electron microscopy and UV-vis spectra. (C) 2016 Elsevier B.V. All rights reserved.
摘要:
The authors describe a strategy for fluorometric determination of lead(II) that is based on the suppression of the surface energy transfer that occurs between acridine orange and gold nanoparticles (AuNPs). As a result, the fluorescence of the system is recovered. Under optimized conditions, the enhancement of fluorescence intensity is related to the concentration of lead(II) in the 44 nM to 4.8 μM range, with a detection limit of 13 nM. The relative standard deviations for 11 determinations at concentrations of 0.386 μM, 1.93 μM and 2.89 μM are 1.02 %, 1.06 % and 1.75 %, respectively. This result suggests that the method can potentially be used to monitor the level of lead(II) in environmental samples. Lead(II) ion is found to bind to citrate capped gold nanoparticles (AuNPs) which prevents binding of acridine orange (AO) to the AuNPs. As a result, the surface energy transfer from AO to AuNPs cannot occur and fluorescence is restored. This effect was used to quantify lead(II) ion.
摘要:
A kind of functional plant composite adsorbent was prepared through diethylenetriamine modifing the Cycas revoluta leaves for low concentration of U(VI) in waste water. The dynamic behavior of the adsorption, the Langmuir and Freundlich equations and the thermodynamic parameters was were also examined in the present study. The experimental results showed that diethylenetriamine functionalized Cycas revoluta leaves used for low concentration of uranium possessed many advantages such as widely raw material sources, simple and economy for preparation, less adsorbent dosage, short balance time, high adsorption efficiency, good chemical and mechanical stability, and can be effective regeneration or reused.
摘要:
The fabrication of tiron-copper complex as a novel fluorescence probe for the sensitive directly detection of metallothioneins at nanomolar levels was demonstrated. In Britton-Robinson (B-R) buffer (pH 7.50), the interaction of bis(firon)copper(II) complex cation [Cu(tiron)(2)](2+) and metallothioneins enhanced the fluorescence intensity of the system. The fluorescence enhancement at 347 nm was proportional to the concentration of metallothioneins. The mechanism was studied and discussed in terms of the fluorescence spectra. Under the optimal experimental conditions, at 347 nm, there was a linear relationship between the fluorescence intensity and the concentration of the metallothioneins in the range of 8.80 x 10(-9)-7.70 x 10(-7) mol L-1, with a correlation coefficient of r = 0.995 and detection limit 2.60 x 10(-9) mol L-1. The relative standard deviation was 0.77% (n = 11), and the average recovery 94.4%. The method proposed was successfully reliable, selective and sensitive in determining of trace metallothioneins in fish visceral organ samples with the results in good agreement with those obtained by HPLC. (C) 2015 Elsevier B.V. All rights reserved.