scholarly journals Effective reduction of nitrophenols and colorimetric detection of Pb(ii) ions by Siraitia grosvenorii fruit extract capped gold nanoparticles

RSC Advances ◽  
2021 ◽  
Vol 11 (25) ◽  
pp. 15438-15448
Author(s):  
Van Thuan Le ◽  
Truong Giang Duong ◽  
Van Tan Le ◽  
Thanh Long Phan ◽  
Thi Lan Huong Nguyen ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Colorimetric Detection ◽  
High Sensitivity ◽  
Fruit Extract ◽  
Siraitia Grosvenorii ◽  
Effective Reduction ◽  
Sensitivity And Selectivity

Siraitia grosvenorii fruit extract capped AuNPs exhibited excellent catalytic activity in the reduction of nitrophenols and high sensitivity and selectivity for detection of Pb(ii) ions.

Stable gold nanoparticles as a novel peroxidase mimic for colorimetric detection of cysteine

2016 ◽  
Vol 8 (11) ◽  
pp. 2494-2501 ◽  
Author(s):  
Rong Sheng Li ◽  
Hai Liu ◽  
Bin Bin Chen ◽  
Hong Zhi Zhang ◽  
Cheng Zhi Huang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Colorimetric Detection ◽  
High Sensitivity ◽  
Peroxidase Mimic ◽  
Sensitivity And Selectivity ◽  
Blue Solution

In this work, stable gold nanoparticles (AuNPs) were prepared with good compatibility and favorable catalytic activity. They were developed as a peroxidase mimic for colorimetric detection of cysteine with a weakened blue solution, which supplied high sensitivity and selectivity.

One-pot synthesized DNA-templated Ag/Pt bimetallic nanoclusters as peroxidase mimics for colorimetric detection of thrombin

2014 ◽  
Vol 50 (86) ◽  
pp. 13103-13106 ◽  
Author(s):  
Cheng Zheng ◽  
Ai-Xian Zheng ◽  
Bo Liu ◽  
Xiao-Long Zhang ◽  
Yu He ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Colorimetric Detection ◽  
Protein Detection ◽  
High Sensitivity ◽  
One Pot ◽  
Highly Efficient ◽  
Bimetallic Nanoclusters ◽  
Peroxidase Mimics ◽  
Sensitivity And Selectivity ◽  
Colorimetric Aptasensor

One-pot synthesized DNA-templated Ag/Pt bimetallic nanoclusters possess highly-efficient peroxidase-like catalytic activity and are applied to design a colorimetric aptasensor for the protein detection with high sensitivity and selectivity.

scholarly journals Smartphone-Based Colorimetric Detection of Chromium (VI) by Maleic Acid-Functionalized Gold Nanoparticles

2021 ◽  
Vol 11 (22) ◽  
pp. 10894
Author(s):  
Ahmed Mohamed ◽  
Xuemeng Li ◽  
Chengfei Li ◽  
Xuegang Li ◽  
Chao Yuan ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Maleic Acid ◽  
Colorimetric Detection ◽  
High Sensitivity ◽  
Quantitative Detection ◽  
Resource Constrained ◽  
Functionalized Gold Nanoparticles ◽  
Chromium Vi ◽  
Red Color ◽  
Sensitivity And Selectivity

Because of the significant environmental pollution produced by human activities, there is an ongoing need to develop transportable, simple, and reliable techniques for determining trace contaminants on the spot. This work reported a colorimetric detection method for aqueous Cr(VI) sensing by maleic acid-functionalized gold nanoparticles with high sensitivity and selectivity. The wine-red color of the probe solution can change to gray even in the presence of 1.0 µg L−1 of aqueous Cr(VI). Moreover, with the assistance of a smartphone installed with a commercially available color scan application software, its concentration of could be readily quantified on the spot without the help of UV-Vis spectrometer. The detection limit could reach as low as 0.1 µg L−1 with linear range from 0.2 to 2.0 µg L−1. Most importantly, the coefficient variation of the proposed smartphone-based method was equivalent to that of colorimetry, demonstrating the high accuracy of the proposed method for accurate detection of Cr(VI) in resource-constrained countries. Conclusively, with the help of the smartphone, this nanomaterials-based probe demonstrated the potential in the field of environment monitoring for on-site quantitative detection of any pollutants in resource-constrained countries.

scholarly journals Copper (II) Ion-Modified Gold Nanoclusters as Peroxidase Mimetics for the Colorimetric Detection of Pyrophosphate

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5538
Author(s):  
Yunjing Shi ◽  
Jinjie Wang ◽  
Kun Mu ◽  
Suqin Liu ◽  
Guang Yang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Detection Limit ◽  
Chemical Stability ◽  
Human Urine ◽  
Detection Method ◽  
Colorimetric Detection ◽  
Gold Nanoclusters ◽  
High Sensitivity ◽  
Sensitivity And Selectivity ◽  
Optimized Conditions

Copper (II) ions have been shown to greatly improve the chemical stability and peroxidase-like activity of gold nanoclusters (AuNCs). Since the affinity between Cu2+ and pyrophosphate (PPi) is higher than that between Cu2+ and AuNCs, the catalytic activity of AuNCs-Cu2+ decreases with the introduction of PPi. Based on this principle, a new colorimetric detection method of PPi with high sensitivity and selectivity was developed by using AuNCs-Cu2+ as a probe. Under optimized conditions, the detection limit of PPi was 0.49 nM with a linear range of 0.51 to 30,000 nM. The sensitivity of the method was three orders of magnitude higher than that of a fluorescence method using AuNCs-Cu2+ as the probe. Finally, the AuNCs-Cu2+ system was successfully applied to directly determine the concentration of PPi in human urine samples.

scholarly journals A simple and sensitive sensor for silver ions based on unmodified gold nanoparticles by using dynamic light scattering techniques

2017 ◽  
Vol 95 (12) ◽  
pp. 1267-1272 ◽  
Author(s):  
Zhiyou Xiao ◽  
Anjiang Tang ◽  
Hongsheng Huang ◽  
Ze Wang
Keyword(s):  
Gold Nanoparticles ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
High Sensitivity ◽  
Silver Ions ◽  
Hydrodynamic Diameter ◽  
Optimum Conditions ◽  
Sensitivity And Selectivity ◽  
Sensitive Sensor ◽  
Average Hydrodynamic Diameter

A simple and sensitive assay for Ag+ was developed with unmodified gold nanoparticles (AuNPs) by using dynamic light scattering techniques. Ag+ could induce the oligonucleotide (5′-ATC ACT ATA TCA TAT ACT CAT-3′) to change from a single-stranded structure to a double-stranded structure and desorb from the surface of AuNPs, which triggered the aggregation of AuNPs in the salt solution. The average hydrodynamic diameter of aggregated AuNPs could be detected by using dynamic light scattering techniques. Under the optimum conditions, the average hydrodynamic diameter of AuNPs is proportional to the concentration of Ag+ within the range of 13.3–100.0 nmol/L, with a detection limit of 3.2 nmol/L. The method is easy to operate and has low sample consumption, high sensitivity and selectivity.

scholarly journals Enhancement of the Peroxidase-Like Activity of Iodine-Capped Gold Nanoparticles for the Colorimetric Detection of Biothiols

Biosensors ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 113 ◽  
Author(s):  
Chia-Chen Chang ◽  
Tsz-Lian Hsu ◽  
Chie-Pein Chen ◽  
Chen-Yu Chen
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Detection Limit ◽  
Enzymatic Activity ◽  
Catalytic Properties ◽  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Synergetic Effect ◽  
Vis Spectroscopy ◽  
Wide Range

A colorimetric assay was developed for the detection of biothiols, based on the peroxidase-like activity of iodine-capped gold nanoparticles (AuNPs). These AuNPs show a synergetic effect in the form of peroxidase-mimicking activity at the interface of AuNPs, while free AuNPs and iodine alone have weak catalytic properties. Thus, iodine-capped AuNPs possess good intrinsic enzymatic activity and trigger the oxidation of 3,3’,5,5’-tetramethylbenzidine (TMB), leading to a change in color from colorless to yellow. When added to solution, biothiols, such as cysteine, strongly bind to the interface of AuNPs via gold-thiol bonds, inhibiting the catalytic activity of AuNPs, resulting in a decrease in oxidized TMB. Using this strategy, cysteine could be linearly determined, at a wide range of concentrations (0.5 to 20 μM), with a detection limit of 0.5 μM using UV-Vis spectroscopy. This method was applied for the detection of cysteine in diluted human urine.

scholarly journals Colorimetric Detection of Sulfide Anions via Redox-Modulated Surface Chemistry and Morphology of Au-Hg Nanorods

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaotian Zhu ◽  
Chang Liu ◽  
Jie Liu
Keyword(s):  
Surface Chemistry ◽  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
High Sensitivity ◽  
Localized Surface Plasmon ◽  
Wavelength Shift ◽  
Colorimetric Sensing ◽  
Leather Industry ◽  
Colorimetric Response ◽  
Sensitivity And Selectivity

A new colorimetric assay for the detection of sulfide anions with high sensitivity and selectivity is reported, utilizing Au-Hg alloy nanorods (Au-HgNRs) as probe. Au-HgNRs were prepared by modifying gold nanorods (AuNRs) with reducing agent and mercury ions. In an aqueous solution with sulfide anions, the formation of mercuric sulfide due to redox reaction between the amalgams and sulfide anions greatly changed the surface chemistry and morphology of the Au-HgNRs, leading to a red shift of the localized surface plasmon resonance (LSPR) absorption peak, accompanied by a change in colorimetric response. A good linear relationship was obtained between the LSPR peak wavelength shift and concentration of sulfide anion in the range of 1 × 10−5−1 × 10−4 mol/L. The selectivity of this method has been investigated by other anions. The colorimetric sensing system successfully detected sulfide in wastewater from leather industry.

Improved Detection of Hg2+ in Aqueous Solution with High Sensitivity and Selectivity by Using Mercury-Specific DNA, Sybr Green I and Gold Nanoparticles

2011 ◽  
Vol 239-242 ◽  
pp. 934-939
Author(s):  
Hui Xu ◽  
Shuli Gao ◽  
Jian Nong Chen ◽  
Quan Wen Liu
Keyword(s):  
Gold Nanoparticles ◽  
High Sensitivity ◽  
Sybr Green ◽  
Sybr Green I ◽  
Fluorescence Signal ◽  
Potassium Ions ◽  
Label Free ◽  
Turn On ◽  
Sensitivity And Selectivity ◽  
Fluorescence Turn On

We report a label-free, fast, fluorescence turn on assay for Hg2+detecton by using mercury-specific DNA (MSD), Sybr Green I (SG) and gold nanoparticles (AuNPs). SG efficiently discriminates MSD and MSD/Hg2+complex. The addition of gold nanoparticle decreases the background fluorescence signal further for MSD. The fluorescence intensity of MSD/Hg2+complex keeps constant after addition of AuNPs. This property improves the signal-to-background ratio and decreases the detection limitation further. In addition, the method shows improved selectivity compared with that in the absence of AuNPs. This strategy could be applied to the detection of potassium ions and showed good generality.

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