A gold nanoparticles-based colorimetric assay for alkaline phosphatase detection with tunable dynamic range

2013 ◽  
Vol 43 ◽  
pp. 366-371 ◽  
Author(s):  
Chun Mei Li ◽  
Shu Jun Zhen ◽  
Jian Wang ◽  
Yuan Fang Li ◽  
Cheng Zhi Huang
Keyword(s):  
Gold Nanoparticles ◽  
Alkaline Phosphatase ◽  
Dynamic Range ◽  
Colorimetric Assay

Fluorosurfactant-capped gold nanoparticles-based label-free colorimetric assay for Au3+ with tunable dynamic range via a redox strategy

2013 ◽  
Vol 48 ◽  
pp. 1-5 ◽  
Author(s):  
Bin Yang ◽  
Xiao-Bing Zhang ◽  
Wei-Na Liu ◽  
Rong Hu ◽  
Weihong Tan ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Dynamic Range ◽  
Colorimetric Assay ◽  
Label Free

An Effort to Making a Colorimitric Nano-Biosensor for Vibrio cholera Detection

2020 ◽  
Vol 16 (5) ◽  
pp. 793-804
Author(s):  
Naimeh Mahheidari ◽  
Jamal Rashidiani ◽  
Hamid Kooshki ◽  
Khadijeh Eskandari
Keyword(s):  
Gold Nanoparticles ◽  
Colorimetric Assay ◽  
Au Nanoparticle ◽  
Bacteria Detection ◽  
Great Promise ◽  
Bacterial Cells ◽  
Vibrio Cholera ◽  
Minimum Concentration ◽  
Vis Spectroscopy ◽  
Fast Procedure

Background: Today, nanoparticles hold great promise in biomedical researches and applications including bacteria detection. The rapid and sensitive outcomes of bacteria detection strategies using nanoparticle conjugates become determinative, especially in bacterial outbreaks. In the current research, we focused on detecting V. cholera bacteria and its toxin using a thiocyanate/Au nanoparticle. Thiocyanate adsorbed strongly on the surface of gold nanoparticles and changed the surface by enhancing surface plasmon resonance of gold nanoparticles. Objective: This method is tried to introduce a simple and fast procedure to assay vibrio cholera. So, it is observed by the naked eyes as well. Methods: We used two antibodies (Ab) for V. cholera detection: a) a primary antibody conjugated to magnetic nanoparticles (MNPs) for trapping V. cholera bacterial cells, and b) a secondary Abconjugated thiocyanate-GNPs as a colorimetric detector. Then, an immuno-magnetic separation system connected to a colorimetric assay was designed based on the GNPs. The results were measured by ultraviolet-visible (UV-Vis) spectroscopy. Results: The results showed that gold nanoparticles are an appropriate optical assay for detecting biological samples in a minimum concentration and also it can be easily seen by the naked eyes. The linear range of this biosensor is 3.2×104 to 28×104 cells per ml. Conclusion: In this research, a colorimetric immune assay based on gold nanoparticles was designed to improve the sensitivity of V. cholera detection. Also, this method can be used for the detection of other biological agents.

scholarly journals A dual colorimetric probe for rapid environmental monitoring of Hg2+ and As3+ using gold nanoparticles functionalized with d-penicillamine

RSC Advances ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 5456-5465
Author(s):  
Su-Jin Yoon ◽  
Yun-Sik Nam ◽  
Yeonhee Lee ◽  
In Hwan Oh ◽  
Kang-Bong Lee
Keyword(s):  
Gold Nanoparticles ◽  
Environmental Monitoring ◽  
Colorimetric Assay ◽  
Colorimetric Probe ◽  
Highly Sensitive ◽  
Dual Detection

A highly sensitive and selective colorimetric assay for the dual detection of Hg2+ and As3+ using gold nanoparticles (AuNPs) conjugated with d-penicillamine (DPL) was developed.

scholarly journals Placental Lactogen-I (PL-I) Target Tissues Identified with an Alkaline Phosphatase-PL-I Fusion Protein

1998 ◽  
Vol 46 (6) ◽  
pp. 737-743 ◽  
Author(s):  
Heiner Müller ◽  
Guoli Dai ◽  
Michael J. Soares
Keyword(s):  
Alkaline Phosphatase ◽  
Fusion Protein ◽  
Colorimetric Assay ◽  
Biological Activities ◽  
Placental Lactogen ◽  
Kidney Cells ◽  
Fetal Kidney ◽  
Transfected Cells ◽  
Tissue Sections ◽  
Labeling System

The rat placenta expresses a family of genes related to prolactin (PRL). Target tissues and physiological roles for many members of the PRL family have yet to be determined. In this investigation we evaluated the use of an alkaline phosphatase (AP) tag for monitoring the behavior of a prototypical member of the PRL family, placental lactogen-I (PL-I). A probe was generated consisting of a fusion protein of human placental AP and rat PL-I (AP-PL-I). The AP-PL-I construct was stably expressed in 293 human fetal kidney cells, as was the unmodified AP vector that served as a control. AP activity was monitored with a colorimetric assay in conditioned medium from transfected cells. Immunoreactivity and PRL-like biological activities of the AP-PL-I fusion protein were demonstrated by immunoblotting and the Nb2 lymphoma cell proliferation assay, respectively. AP-PL-I specifically bound to tissue sections known to express the PRL receptor, including the ovary, liver, and choroid plexus. Binding of AP-PL-I to tissues was specific and could be competed with ovine PRL. The results indicate that AP is an effective tag for monitoring the behavior of PL-I and suggest that this labeling system may also be useful for monitoring the actions of other members of the PRL family.

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 Development of Label-Free Colorimetric Assay for MERS-CoV Using Gold Nanoparticles

ACS Sensors ◽  
2019 ◽  
Vol 4 (5) ◽  
pp. 1306-1312 ◽  
Author(s):  
Hanbi Kim ◽  
Minseon Park ◽  
Joonki Hwang ◽  
Jin Hwa Kim ◽  
Doo-Ryeon Chung ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Colorimetric Assay ◽  
Label Free

A kinetic colorimetric assay of gamma-glutamyltransferase.

1986 ◽  
Vol 32 (8) ◽  
pp. 1581-1584 ◽  
Author(s):  
P Fossati ◽  
G V Melzi d'Eril ◽  
G Tarenghi ◽  
L Prencipe ◽  
G Berti
Keyword(s):  
Dynamic Range ◽  
Colorimetric Assay ◽  
Colorimetric Method ◽  
Volume Ratio ◽  
Ascorbate Oxidase ◽  
Good Precision ◽  
Gamma Glutamyltransferase ◽  
Gamma Glutamyl ◽  
Donor Substrate ◽  
Donor And Acceptor

Abstract We have explored a kinetic colorimetric method for measuring gamma-glutamyltransferase (EC 2.3.2.2) activity in serum, using L-gamma-glutamyl-3,5-dibromo-4-hydroxyanilide and glycylglycine as donor and acceptor substrates. The released product, 3,5-dibromo-4-hydroxyaniline, reacts with 2,5-dimethylphenol to produce a blue quinone monoimine in the presence of ascorbate oxidase (EC 1.10.3.3). This dye has peak absorption at 610 nm, whereas the donor substrate shows negligible absorption throughout the visible spectrum. The reaction can be run with all the reagents in a single working solution with serum as starter, or with the substrate solution as starting reagent. The sample/reagent volume ratio is 1:24. Adaptation of the method to several automated instruments gave good precision in all cases. Comparison with a method in which L-gamma-glutamyl-3-carboxy-4-nitroanilide is the donor substrate showed good correlation of results (r greater than or equal to 0.987). The dynamic range of the method exceeds the upper limits of the reference intervals for men (9-33 U/L) and women (8-25 U/L) by at least 18-fold.

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