A colorimetric assay of dopamine utilizing melamine modified gold nanoparticle probes

2015 ◽  
Vol 7 (3) ◽  
pp. 838-841 ◽  
Author(s):  
Zhengbo Chen ◽  
Chenmeng Zhang ◽  
Cong Wang

A colorimetric assay of dopamine utilizing melamine modified gold nanoparticles.

2000 ◽  
Vol 72 (1-2) ◽  
pp. 229-235 ◽  
Author(s):  
Robert A. Reynolds ◽  
Chad A. Mirkin ◽  
Robert L. Letsinger

An exceptionally simple and effective DNA detection methodology based on latex microsphere and gold nanoparticle probes has been developed. The latex and gold particle probes, which were functionalized with separate oligonucleotide sequences, undergo hybridization in the presence of target strands that are complementary to both of the probes. Duplex formation thus results in linking of gold nanoparticles to the latex microspheres and a corresponding white-to-red color change, which, because of the particularly large extinction coefficient of the gold nanoparticles, is clearly visible to the naked eye. Background signal caused by unbound gold nanoparticles is significantly reduced by filtering the solution containing the sample and probes through a size-selective cellulose acetate membrane. The unbound gold probes move freely through this membrane while the larger latex particles are trapped. Therefore, if the latex and gold nanoparticles are joined together via the target oligonucleotides, the membrane appears red, indicating a positive test result. If no hybridization takes place, the membrane appears white, indicating a negative result. The lower detection limits for this system are 500 pM for a 24 base single-stranded target and 2.5 nM for a duplex target oligonucleotide.


RSC Advances ◽  
2014 ◽  
Vol 4 (83) ◽  
pp. 43998-44003 ◽  
Author(s):  
Jingting Hu ◽  
Haichao Dai ◽  
Yujing Sun ◽  
Pengjuan Ni ◽  
Yilin Wang ◽  
...  

A sensitive aptamer-based colorimetric biosensor for the detection of ricin using unmodified gold nanoparticles as probe was developed.


2017 ◽  
Vol 53 (54) ◽  
pp. 7477-7480 ◽  
Author(s):  
Juanhua Yang ◽  
Yun Zhang ◽  
Lang Zhang ◽  
Huili Wang ◽  
Jinfang Nie ◽  
...  

This work reports a new nanosensor based on analyte-triggered autocatalytic amplification and label-free gold nanoparticles for the colorimetric detection of Hg2+, Cu2+and Ag+with detection limits less than 3 nM.


2020 ◽  
Vol 2 (12) ◽  
pp. 5737-5745
Author(s):  
Tejaswini Appidi ◽  
Sushma V. Mudigunda ◽  
Suseela Kodandapani ◽  
Aravind Kumar Rengan

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


2017 ◽  
Vol 9 (19) ◽  
pp. 2805-2811 ◽  
Author(s):  
Jianyu Wei ◽  
Luming Yang ◽  
Guozong Yue ◽  
Jing Zhu ◽  
Deshun Huang ◽  
...  

Nitrilotriacetate (NTA) has been reported to behave as both a reductant and a stabilizer for gold nanoparticle (AuNP) preparation in a one-pot synthesis and colorimetric assay.


Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 861 ◽  
Author(s):  
Chia-Chen Chang ◽  
Chie-Pein Chen ◽  
Tzu-Heng Wu ◽  
Ching-Hsu Yang ◽  
Chii-Wann Lin ◽  
...  

Gold nanoparticles are popularly used in biological and chemical sensors and their applications owing to their fascinating chemical, optical, and catalytic properties. Particularly, the use of gold nanoparticles is widespread in colorimetric assays because of their simple, cost-effective fabrication, and ease of use. More importantly, the gold nanoparticle sensor response is a visual change in color, which allows easy interpretation of results. Therefore, many studies of gold nanoparticle-based colorimetric methods have been reported, and some review articles published over the past years. Most reviews focus exclusively on a single gold nanoparticle-based colorimetric technique for one analyte of interest. In this review, we focus on the current developments in different colorimetric assay designs for the sensing of various chemical and biological samples. We summarize and classify the sensing strategies and mechanism analyses of gold nanoparticle-based detection. Additionally, typical examples of recently developed gold nanoparticle-based colorimetric methods and their applications in the detection of various analytes are presented and discussed comprehensively.


2020 ◽  
Vol 16 (5) ◽  
pp. 793-804
Author(s):  
Naimeh Mahheidari ◽  
Jamal Rashidiani ◽  
Hamid Kooshki ◽  
Khadijeh Eskandari

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.


2020 ◽  
Vol 16 (2) ◽  
pp. 204-213 ◽  
Author(s):  
Melissa A. Vetten ◽  
Mary Gulumian

Background: Endotoxin-free engineered nanoparticle suspensions are imperative for their successful applications in the field of nanomedicine as well as in the investigations in their toxicity. Gold nanoparticles are known to interfere with various in vitro assays due to their optical properties and potential for surface reactivity. In vitro endotoxin testing assays are known to be susceptible to interference caused by the sample being tested. Objective: This study aimed to identify a preferred assay for the testing of endotoxin contamination in gold nanoparticle suspensions. Methods: The interference by gold nanoparticles on three assays namely, the commonly used limulus amebocyte lysate chromogenic assay, the limulus amebocyte lysate gel-clot method, and the less common recombinant Factor C (rFC) assay, was tested. Results: Possible interference could be observed with all three assays. The interference with the absorbance- based chromogenic assay could not be overcome by dilution; whilst the qualitative nature of the gel-clot assay excluded the possibility of distinguishing between a false positive result due to enhancement of the sensitivity of the assay, and genuine endotoxin contamination. However, interference with the rFC assay was easily overcome through dilution. Conclusion: The rFC assay is recommended as an option for endotoxin contamination detection in gold nanoparticle suspensions.


2021 ◽  
Author(s):  
Yiren Cao ◽  
Jinjun Wu ◽  
Bo Pang ◽  
Hongquan Zhang ◽  
X. Chris Le

The trans-cleavage activity of the target-activated CRISPR-Cas12a liberated an RNA crosslinker from a molecular transducer, which facilitated assembly of gold nanoparticles. Integration of the molecular transducer with isothermal amplification and...


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

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.


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