High-throughput and ultratrace naked-eye colorimetric detection of Au3+ based on the gold amalgam-stimulated peroxidase mimetic activity in aqueous solutions

2017 ◽  
Vol 53 (36) ◽  
pp. 5056-5058 ◽  
Author(s):  
Shouting Zhang ◽  
Zhuoyue Zhang ◽  
Tiansheng Wang ◽  
Dongxu Zhang ◽  
Xuemei Li ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
High Throughput ◽  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Label Free ◽  
Efficient Strategy ◽  
Naked Eye ◽  
Peroxidase Mimetic

Herein, we present a catalysis-based, label-free, and efficient strategy for a rapid, high-throughput, highly selective and ultrasensitive naked-eye colorimetric assay of Au3+ in aqueous solutions, based on the gold amalgam-stimulated peroxidase mimetic activity.

Colorimetric detection of class A soybean saponins by coupling DNAzyme with the gap ligase chain reaction

2020 ◽  
Vol 12 (26) ◽  
pp. 3361-3367
Author(s):  
Wenshuai Li ◽  
Guorui Wu ◽  
Min Wang ◽  
Aiqin Yue ◽  
Weijun Du ◽  
...  
Keyword(s):  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Chain Reaction ◽  
Ligase Chain Reaction ◽  
Naked Eye ◽  
Class A

We propose a colorimetric assay based on the coupling of gap ligase chain reaction (Gap-LCR) with DNAzyme to detect the target GmSg-1 genes of class A soybean saponins with the naked eye, without the involvement of expensive instruments.

scholarly journals Phytosynthesis of Palladium Nanoclusters: An Efficient Nanozyme for Ultrasensitive and Selective Detection of Reactive Oxygen Species

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3349
Author(s):  
Ravi Mani Tripathi ◽  
Sang J. Chung
Keyword(s):  
Reactive Oxygen Species ◽  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Reactive Oxygen ◽  
Cost Effective ◽  
Oxygen Species ◽  
Distribution Profile ◽  
Fenton’S Reaction ◽  
Peroxidase Mimetic ◽  
H2o2 Detection

Hydrogen peroxide is a low-reactivity reactive oxygen species (ROS); however, it can easily penetrate cell membranes and produce highly reactive hydroxyl radical species through Fenton’s reaction. Its presence in abnormal amounts can lead to serious diseases in humans. Although the development of a simple, ultrasensitive, and selective method for H2O2 detection is crucial, this remains a strategic challenge. The peroxidase mimetic activity of palladium nanoclusters (PdNCs) has not previously been evaluated. In this study, we developed an ultrasensitive and selective colorimetric detection method for H2O2 using PdNCs. An unprecedented eco-friendly, cost-effective, and facile biological method was developed for the synthesis of PdNCs. This is the first report of the biosynthesis of PdNCs. The synthesized nanoclusters had a significantly narrow size distribution profile and high stability. The nanoclusters were demonstrated to possess a peroxidase mimetic activity that could oxidize peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB). Various interfering substances in serum (100 μM phenylalanine, cysteine, tryptophan, arginine, glucose, urea, Na+, Fe2+, PO43−, Mn+2, Ca2+, Mg2+, Zn2+, NH4+, and K+) were included to evaluate the selectivity of the assay, and oxidation of TMB occurred only in the presence of H2O2. Therefore, PdNCs show an efficient nanozyme for the peroxidase mimetic activity. The assay produced a sufficient signal at the ultralow concentration of 0.0625 µM H2O2. This colorimetric assay provides a real-time, rapid, and easy-to-use platform for the detection of H2O2 for clinical purposes.

scholarly journals Label-Free Colorimetric Detection of Urine Glucose Based on Color Fading Using Smartphone Ambient-Light Sensor

Chemosensors ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 10 ◽  
Author(s):  
Wang ◽  
Guo ◽  
Hu ◽  
Liang ◽  
Li ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Colorimetric Assay ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Diabetic Patients ◽  
Ambient Light ◽  
Label Free ◽  
Urine Glucose ◽  
Light Sensor

In this work, a label-free colorimetric assay was developed for the determination of urine glucose using smartphone ambient-light sensor (ALS). Using horseradish peroxidase—hydrogen peroxide—3,3′,5,5′-tetramethylbenzidine (HRP-H2O2-TMB) colored system, quantitative H2O2 was added to samples to-be-determined for deepest color. The presence of glucose oxidase in urine led to the formation of H2O2 and the reduction of TMBred. As a result of this, the color of the urine faded and the solution changed from deep blue to light blue. We measured the illuminance of the transmitted light by a smartphone ambient light sensor, and thereby color changes were used to calculate the content of urine glucose. After method validation, this colorimetric assay was practically applied for the determination of urine samples from diabetic patients. Good linearity was obtained in the range of 0.039–10.000 mg/mL (R2 = 0.998), and a limit of detection was 0.005 mg/mL. Our method was had high accuracy, sensitivity, simplicity, rapidity, and visualization, providing a new sensor to be potentially applicable for point-of-care detection of urine glucose.

scholarly journals Development of label-free gold nanoparticle based rapid colorimetric assay for clinical/point-of-care screening of cervical cancer

2020 ◽  
Vol 2 (12) ◽  
pp. 5737-5745
Author(s):  
Tejaswini Appidi ◽  
Sushma V. Mudigunda ◽  
Suseela Kodandapani ◽  
Aravind Kumar Rengan
Keyword(s):  
Cervical Cancer ◽  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Colorimetric Assay ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Label Free ◽  
Free Gold ◽  
Clinical Point

“C-ColAur” technique for colorimetric detection of cervical cancer by in situ formation of gold nanoparticles.

Colorimetric assay of Hg2+ based on the inhibition of peroxidase mimetic activity of gold nanoclusters induced by Hg2+

2019 ◽  
Vol 11 (16) ◽  
pp. 2179-2182 ◽  
Author(s):  
Xueding Jiang ◽  
Weicheng Xu ◽  
Xin Chen ◽  
Yong Liang
Keyword(s):  
Aqueous Solutions ◽  
Colorimetric Assay ◽  
Gold Nanoclusters ◽  
Peroxidase Mimetic ◽  
Highly Sensitive

In this paper, we report a highly sensitive and selective colorimetric assay for Hg2+ detection in aqueous solutions.

Gold nanoparticle-based exonuclease III signal amplification for highly sensitive colorimetric detection of folate receptor

Nanoscale ◽  
2014 ◽  
Vol 6 (6) ◽  
pp. 3055-3058 ◽  
Author(s):  
Xinjian Yang ◽  
Zhiqiang Gao
Keyword(s):  
Gold Nanoparticles ◽  
Small Molecule ◽  
Signal Amplification ◽  
Colorimetric Assay ◽  
Folate Receptor ◽  
Colorimetric Detection ◽  
Label Free ◽  
Exonuclease Iii ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

By combining terminal protection of small molecule (folate)-capped DNA probes, exonuclease III signal amplification and gold nanoparticles, we developed a simple and label-free colorimetric assay for highly sensitive detection of folate receptor.

scholarly journals Label-free colorimetric detection of glutathione by autocatalytic oxidation of o-phenylenediamine based on Au3+ regulation and its application

2021 ◽  
Author(s):  
Shaoguang Li ◽  
Huilin Liu ◽  
Xiaoying Zhang ◽  
Jiasong Cai ◽  
Kunlong Huang ◽  
...  
Keyword(s):  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Label Free ◽  
Highly Sensitive ◽  
Autocatalytic Oxidation

A label-free, rapid, and highly sensitive colorimetric assay for the detection of glutathione (GSH) was developed.

Directed Evolution of P450 Fatty Acid Decarboxylases via High-Throughput Screening Towards Improved Catalytic Activity

2019 ◽  
Author(s):  
Huifang Xu ◽  
Weinan Liang ◽  
Linlin Ning ◽  
Yuanyuan Jiang ◽  
Wenxia Yang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Fatty Acid ◽  
Directed Evolution ◽  
High Throughput ◽  
High Throughput Screening ◽  
Colorimetric Detection ◽  
Screening Method ◽  
Random Mutagenesis ◽  
Direct Production ◽  
Consumption Activity

P450 fatty acid decarboxylases (FADCs) have recently been attracting considerable attention owing to their one-step direct production of industrially important 1-alkenes from biologically abundant feedstock free fatty acids under mild conditions. However, attempts to improve the catalytic activity of FADCs have met with little success. Protein engineering has been limited to selected residues and small mutant libraries due to lack of an effective high-throughput screening (HTS) method. Here, we devise a catalase-deficient <i>Escherichia coli</i> host strain and report an HTS approach based on colorimetric detection of H<sub>2</sub>O<sub>2</sub>-consumption activity of FADCs. Directed evolution enabled by this method has led to effective identification for the first time of improved FADC variants for medium-chain 1-alkene production from both DNA shuffling and random mutagenesis libraries. Advantageously, this screening method can be extended to other enzymes that stoichiometrically utilize H<sub>2</sub>O<sub>2</sub> as co-substrate.

scholarly journals Pt Nanoparticles Anchored on NH2-MIL-101 with Efficient Peroxidase-Like Activity for Colorimetric Detection of Dopamine

Chemosensors ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 140
Author(s):  
Jing Li ◽  
Keying Xu ◽  
Yang Chen ◽  
Jie Zhao ◽  
Peiyao Du ◽  
...  
Keyword(s):  
Active Sites ◽  
Clinical Medicine ◽  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Pt Nanoparticles ◽  
Robust Detection ◽  
Color Changes ◽  
Relevant Role ◽  
Metal Organic ◽  
The Central Nervous System

Dopamine (DA) is an important catecholamine neurotransmitter that plays a highly relevant role in regulating the central nervous system, and abnormal DA content can cause many immune-related diseases. Hence, it is of significance to sensitively and specifically identify DA for clinical medicine. In this work, Pt/NH2-MIL-101 hybrid nanozymes with bimetallic catalytic centers were fabricated by forming coordinate bonds between Pt nanoparticles (Pt NPs) and –NH2 on metal–organic frameworks (MOF). The catalytic activity of Pt/NH2-MIL-101 was increased by 1.5 times via enlarging the exposure of more active sites and improving the activity of the active sites through the strategy of forming bimetallic catalytic centers. In the presence of DA, competing with 3, 3′, 5, 5′-tetramethylbenzidine (TMB) for the generated hydroxyl radicals (•OH), the blue oxidation state TMB (Ox-TMB) is reduced to colorless TMB, showing dramatic color changes. The Pt/NH2-MIL-101-based colorimetric assay enables the sensitive and robust detection of DA molecules with a detection limit of only 0.42 μM and has an observable potential in clinical applications.

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