Label-Free Colorimetric Detection of Lead Ions with a Nanomolar Detection Limit and Tunable Dynamic Range by using Gold Nanoparticles and DNAzyme

2008 ◽  
Vol 20 (17) ◽  
pp. 3263-3267 ◽  
Author(s):  
Zidong Wang ◽  
Jung Heon Lee ◽  
Yi Lu
Keyword(s):  
Gold Nanoparticles ◽  
Detection Limit ◽  
Dynamic Range ◽  
Colorimetric Detection ◽  
Lead Ions ◽  
Label Free ◽  
Nanomolar Detection

A label-free colorimetric detection of lead ions by controlling the ligand shells of gold nanoparticles

Talanta ◽  
2010 ◽  
Vol 82 (2) ◽  
pp. 516-522 ◽  
Author(s):  
Yu-Lun Hung ◽  
Tung-Ming Hsiung ◽  
Yi-You Chen ◽  
Chih-Ching Huang
Keyword(s):  
Gold Nanoparticles ◽  
Colorimetric Detection ◽  
Lead Ions ◽  
Label Free

A Label-Free Colorimetric Biosensor for 17β-Estradiol Detection Using Nanoparticles Assembled by Aptamer and Cationic Polymer

2016 ◽  
Vol 69 (1) ◽  
pp. 12 ◽  
Author(s):  
Dongwei Zhang ◽  
Weilin Zhang ◽  
Jiayun Ye ◽  
Shenshan Zhan ◽  
Bing Xia ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Detection Limit ◽  
Colorimetric Detection ◽  
Cationic Polymer ◽  
Label Free ◽  
Human Beings ◽  
Remarkable Change ◽  
Environment Effects ◽  
Diallyldimethylammonium Chloride ◽  
17Β Estradiol

Concern is mounting regarding the human health and environment effects of 17β-estradiol (E2), a natural oestrogen excreted by human beings and animals. In this paper, a sensitive and selective biosensor for the detection of E2 using gold nanoparticles (AuNPs), label-free E2-specific aptamer, and poly(diallyldimethylammonium chloride) (PDDA) was developed. In the absence of E2, PDDA can electrostatically interact with E2-specific aptamer, and the charge responsible for inducing AuNPs aggregation was destroyed. However, the introduction of E2 can specifically interact with the aptamer to form E2–aptamer complex so that PDDA can aggregate AuNPs and cause a remarkable change in colour from wine red to blue, which enables colorimetric detection of E2 with selectivity and a detection limit of 1.57 nM.

scholarly journals Disulfide-induced self-assembled targets: A novel strategy for the label free colorimetric detection of DNAs/RNAs via unmodified gold nanoparticles

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Ehsan Shokri ◽  
Morteza Hosseini ◽  
Mehdi D. Davari ◽  
Mohammad R. Ganjali ◽  
Maikel P. Peppelenbosch ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Colorimetric Detection ◽  
Label Free ◽  
Self Assembled ◽  
Novel Strategy

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.

Colorimetric Detection of Trace Arsenic(III) in Aqueous Solution Using Arsenic Aptamer and Gold Nanoparticles

2014 ◽  
Vol 67 (5) ◽  
pp. 813 ◽  
Author(s):  
Minglei Yu
Keyword(s):  
Aqueous Solution ◽  
Gold Nanoparticles ◽  
Detection Limit ◽  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Colour Change ◽  
Colorimetric Sensing ◽  
Detection Range ◽  
Colorimetric Indicator ◽  
Blue Solution

In this study, trace arsenic(iii) (AsIII) in aqueous solution was detected by applying a classical aptamer-based gold nanoparticles colorimetric sensing strategy. An arsenic aptamer was used as a sensing probe and gold nanoparticles as a colorimetric indicator. In the absence of AsIII, the gold nanoparticles were stabilised by the arsenic aptamer and remained dispersed at high NaCl concentrations, displaying a red solution. Contrarily, in the presence of AsIII, the gold nanoparticles were prone to aggregation, owing to the formation of aptamer–AsIII complex between the arsenic aptamer and AsIII, and thus exhibited a blue solution. By monitoring the colour change, a simple and fast colorimetric assay for AsIII was established with a detection range of 1.26–200 ppb and a detection limit of 1.26 ppb. Because this colorimetric assay only involves common reagents and can be assessed visually, it holds great potential for arsenic(iii) monitoring in environment-related and other applications.

Colorimetric Detection of DNA Sequences Using an Organic Solvent to Induce the Aggregation of Label-Free Gold Nanoparticles

2013 ◽  
Vol 13 (6) ◽  
pp. 3805-3809 ◽  
Author(s):  
Huning Jia ◽  
Xiaomei Cao ◽  
Cong Fu ◽  
Jianping Wang ◽  
Zhiyao Chen ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Organic Solvent ◽  
Dna Sequences ◽  
Colorimetric Detection ◽  
Label Free ◽  
Free Gold

A Colorimetric Aptamer Biosensor Based on Gold Nanoparticles for the Ultrasensitive and Specific Detection of Tetracycline in Milk

2013 ◽  
Vol 66 (4) ◽  
pp. 485 ◽  
Author(s):  
Lan He ◽  
Yanfang Luo ◽  
Wenting Zhi ◽  
Yuangen Wu ◽  
Pei Zhou
Keyword(s):  
Gold Nanoparticles ◽  
Detection Limit ◽  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Colour Change ◽  
Raw Milk ◽  
Hexadecyltrimethylammonium Bromide ◽  
Specific Detection ◽  
Wide Range

This paper proposes a sensing strategy which employs an aptamer, unmodified gold nanoparticles (AuNP), and hexadecyltrimethylammonium bromide (CTAB) to detect tetracycline (TET) in raw milk. The method is based on the colorimetric assay of aggregating AuNP. In the absence of TET, the CTAB and aptamer form a complex which allows the aggregation of AuNP. In the presence of TET, the TET aptamer is exhausted first due to the formation of aptamer-TET complexes, which prevents assembly of the CTAB–aptamer supramolecule, causing a colour change and no aggregation of AuNP. This mechanism for the detection of TET proved to be sensitive and convenient. The colorimetric assay has a detection limit of 122 nM TET. This sensor has great potential for the sensitive, colorimetric detection of a wide range of molecular analytes.

Sensitive colorimetric detection of cyromazine in cucumber samples by using label-free gold nanoparticles and polythymine

The Analyst ◽  
2015 ◽  
Vol 140 (9) ◽  
pp. 3064-3069 ◽  
Author(s):  
Jinchuan Liu ◽  
Wenhui Bai ◽  
Chao Zhu ◽  
Mengmeng Yan ◽  
Shuming Yang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Colorimetric Detection ◽  
Colorimetric Method ◽  
Label Free ◽  
Free Gold

A sensitive colorimetric method for cyromazine detection in cucumber samples was developed by using label-free gold nanoparticles and polythymine.

Cocaine detection using aptamer and molybdenum disulfide-gold nanoparticle-based sensors

Nanomedicine ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 325-335
Author(s):  
Li Gao ◽  
Wenwen Xiang ◽  
Zebin Deng ◽  
Keqing Shi ◽  
Huixing Wang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Detection Limit ◽  
Molybdenum Disulfide ◽  
Low Cost ◽  
High Sensitivity ◽  
Label Free ◽  
Sensing System ◽  
Plasmon Resonance Band ◽  
Resonance Band ◽  
Cocaine Detection

Aim: The current work highlighted a novel colorimetric sensor based on aptamer and molybdenum disulfide (MoS2)-gold nanoparticles (AuNPs) that was developed for cocaine detection with high sensitivity. Materials & methods: Due to the presence of the plasmon resonance band on the surface of AuNPs, AuNPs aggregated and the color was changed from red to blue after adding a certain concentration of NaCl. We used MoS2 to optimize the sensing system of AuNPs. The folded conformation of the aptamer in combination with cocaine enhanced the salt tolerance of the MoS2-AuNPs, effectively preventing their aggregation. Results & conclusion: The detection limit of cocaine was 7.49 nM with good selectivity. The method based on MoS2-AuNPs colorimetry sensor is simple, quick, label-free and low cost.

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