A gold nanoparticle/latex microsphere-based colorimetric oligonucleotide detection method

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.


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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Sivakavinesan ◽  
M. Vanaja ◽  
G. Annadurai

AbstractThe present work aimed at synthesizing gold nanoparticles in a biological method employing fruit peel waste dumped in the environment. The peels of Garcinia mangostana (Mangostan), were collected from the nearby tourist spot during the season. The collected fruit peels were washed, dried, powder and extracted by using boiling water and acetone. The precipitated extract was dried and powdered for further use. The dried and powdered peel extract was added to the gold solution and boiled to 80 °C and the color change is observed. The color change indicates the completion of the synthesis of gold nanoparticles. The effect of pH, gold ion concentration, peel extract powder concentration, and the temperature was tested by varying the parameters. The biosynthesized nanoparticles were characterized using the UV–Vis spectrophotometer to identify the surface plasmon resonance peaks corresponding to gold nanoparticles. The bio-moieties responsible for the synthesis of gold nanoparticles were identified using the Fourier Transform Infra-Red Spectroscopy. The crystalline nature was detected by using an X-Ray Diffractometer. Atomic Force Microscope viewed the 3D surface image of the gold nanoparticle. The shape and morphology of the nanoparticle were identified by using a Field Emission Scanning Electron Microscope. The active compounds for gold nanoparticle synthesis were identified using Gas Chromatography-Mass Spectrometry. The gold nanoparticle was synthesized in various colors and used for dyeing cotton fabrics. The dyed cotton materials were exposed to various stress conditions to determine the color fastening.


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...


2021 ◽  
Author(s):  
Min Chen ◽  
Leiqing Pan ◽  
K. Tu

A simple and quick responsive fluorescent biosensor for Salmonella typhimurium detection based on the recognition of aptamer coupled with alendronic acid (ADA)@upconversion nanoparticles (UCNPs) and gold nanoparticle (AuNPs) has been...


Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 472
Author(s):  
Qunying Yuan ◽  
Manjula Bomma ◽  
Zhigang Xiao

Phytochelatins, the enzymatic products of phytochelatin synthase, play a principal role in protecting the plants from heavy metal and metalloid toxicity due to their ability to scavenge metal ions. In the present study, we investigated the capacity of soluble intracellular extracts from E. coli cells expressing R. tropici phytochelatin synthase to synthesize gold nanoparticle. We discovered that the reaction mediated by soluble extracts from the recombinant E. coli cells had a higher yield of gold nanoparticles, compared to that from the control cells. The compositional and morphological properties of the gold nanoparticles synthesized by the intracellular extracts from recombinant cells and control cells were similar. In addition, this extracellular nanoparticle synthesis method produced purer gold nanoparticles, avoiding the isolation of nanoparticles from cellular debris when whole cells are used to synthesize nanoparticles. Our results suggested that phytochelatins can improve the efficiency of gold nanoparticle synthesis mediated by bacterial soluble intracellular extracts, and the potential of extracellular nanoparticle synthesis platform for the production of nanoparticles in large quantity and pure form is worth further investigation.


The Analyst ◽  
2017 ◽  
Vol 142 (17) ◽  
pp. 3261-3271 ◽  
Author(s):  
John A. Hondred ◽  
Joyce C. Breger ◽  
Nate T. Garland ◽  
Eunkeu Oh ◽  
Kimihiro Susumu ◽  
...  

A significant enzymatic enhancement of phosphotriesterase has been demonstrated when immobilized on various sized gold nanoparticles.


2016 ◽  
Vol 18 (3) ◽  
pp. 1953-1960 ◽  
Author(s):  
M. C. R. González ◽  
A. G. Orive ◽  
R. C. Salvarezza ◽  
A. H. Creus

Gold nanoparticle electrodeposition on a modified HOPG surface with a monolayer organic film based on aryl diazonium chemistry has been studied.


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