Colorimetric Nucleic Acid Detection Based on Gold Nanoparticles with Branched DNA

NANO ◽  
2020 ◽  
Vol 15 (08) ◽  
pp. 2050110
Author(s):  
Zhikun Zhang ◽  
Xiaojie Ye ◽  
Qingqing Liu ◽  
Cuixia Hu ◽  
Jimmy Yun ◽  
...  

Nucleic acid detection is becoming increasingly important in the diagnostics of genetic diseases for biological analysis. We herein propose gold nanoparticles as probe for colorimetric detection of nucleic acids with branched DNA nanostructures, which enables a novel and simple colorimetric biosensor. In our system, the target DNA specifically triggered two short-chain ssDNA probes to generate branched DNA nanostructures (Y-shape DNA), which prevent AuNPs from aggregation in aqueous NaCl solution. On the contrary, when the target DNA did not exist, gold nanoparticles were unstable and aggregated easily because there is no anti-aggregation function from Y-shape DNA. Sensor response was found to be proportional to the target DNA concentration from 5 to 100[Formula: see text]nM, with detection limits determined as 5[Formula: see text]nM. The developed platform is for colorimetric nucleic acid detection without enzymes, label and modification holds great promise for practical applications.

2018 ◽  
Vol 117 ◽  
pp. 562-566 ◽  
Author(s):  
Feng Li ◽  
Yuhang Dong ◽  
Zhikun Zhang ◽  
Man Lv ◽  
Zhi Wang ◽  
...  

BIOspektrum ◽  
2020 ◽  
Vol 26 (6) ◽  
pp. 624-627
Author(s):  
Ole Behrmann ◽  
Iris Bachmann ◽  
Frank Hufert ◽  
Gregory Dame

Abstract The COVID-19 pandemic highlights the need for fast and simple assays for nucleic acid detection. As an isothermal alternative to RT-qPCR, we outline the development of a detection scheme for SARS-CoV-2 RNA based on reverse transcription recombinase polymerase amplification (RT-RPA) technology. RPA uses recombination proteins in combination with a DNA polymerase for rapid amplification of target DNA at a constant temperature (39–42 °C) within 10 to 20 minutes and can be monitored in real-time with fluorescent probes.


2016 ◽  
Vol 78 ◽  
pp. 200-205 ◽  
Author(s):  
Chia-Chen Chang ◽  
Chen-Yu Chen ◽  
Tsung-Liang Chuang ◽  
Tzu-Heng Wu ◽  
Shu-Chen Wei ◽  
...  

2016 ◽  
Vol 52 (74) ◽  
pp. 11108-11111 ◽  
Author(s):  
Xinya Sun ◽  
Li Wang ◽  
Mingsha Zhao ◽  
Changzhi Zhao ◽  
Shufeng Liu

An autonomous target recycling and cascade circular exponential amplification strategy was proposed for the one-pot, isothermal and ultrasensitive detection of target DNA.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yang You ◽  
Pingping Zhang ◽  
Gengshan Wu ◽  
Yafang Tan ◽  
Yong Zhao ◽  
...  

The recent discovery of collateral cleavage activity of class-II clustered regularly interspaced short palindromic repeats–CRISPR-associated protein (CRISPR-Cas) makes CRISPR-based diagnosis a potential high-accuracy nucleic acid detection method. Colloidal gold-based lateral flow immunochromatographic assay (LFA), which has been combined with CRISPR/Cas-based nucleic detection, usually associates with drawbacks of relative high background and the subjectivity in naked-eye read-out of the results. Here, we developed a novel system composed of Cas12a-based nucleic acid detection and up-converting phosphor technology (UPT)-based LFA (UPT–LFA), termed Cas12a-UPTLFA. We further demonstrated the utility of this platform in highly sensitive and specific detection of Yersinia pestis, the causative agent of the deadly plague. Due to high infectivity and mortality, as well as the potential to be misused as bioterrorism agent, a culture-free, ultrasensitive, specific, and rapid detection method for Y. pestis has long been desired. By incorporating isothermal recombinase polymerase amplification, the Cas12a-UPTLFA we established can successfully detect genomic DNA of Y. pestis as low as 3 attomolar (aM) and exhibited high sensitivity (93.75%) and specificity (90.63%) for detection of spiked blood samples with a detection limit of 102 colony-forming unit per 100 μl of mouse blood. With a portable biosensor, Cas12a-UPTLFA assay can be operated easily by non-professional personnel. Taken together, we have developed a novel Cas12a-UPTLFA platform for rapid detection of Y. pestis with high sensitivity and specificity, which is portable, not expensive, and easy to operate as a point-of-care method. This detection system can easily be extended to detect other pathogens and holds great promise for on-site detection of emerging infectious pathogens.


Author(s):  
Long T. Nguyen ◽  
Brianna M. Smith ◽  
Piyush K. Jain

AbstractThe CRISPR/Cas12a RNA-guided complexes have a tremendous potential for nucleic acid detection due to its ability to indiscriminately cleave ssDNA once bound to a target DNA. However, the current CRISPR/Cas12a systems are limited to detecting DNA in a picomolar detection limit without an amplification step. Here, we developed a platform with engineered crRNAs and optimized conditions that enabled us to detect DNA, DNA/RNA heteroduplex and methylated DNA with higher sensitivity, achieving a limit of detection of in femtomolar range without any target pre-amplification step. By extending the 3’- or 5’-ends of the crRNA with different lengths of ssDNA, ssRNA, and phosphorothioate ssDNA, we discovered a new self-catalytic behavior and an augmented rate of LbCas12a-mediated collateral cleavage activity as high as 3.5-fold compared to the wild-type crRNA. We applied this sensitive system to detect as low as 25 fM dsDNA from the PCA3 gene, an overexpressed biomarker in prostate cancer patients, in simulated urine over 6 hours. The same platform was used to detect as low as ~700 fM cDNA from HIV, 290 fM RNA from HCV, and 370 fM cDNA from SARS-CoV-2, all within 30 minutes without a need for target amplification. With isothermal amplification of SARS-CoV-2 RNA using RT-LAMP, the modified crRNAs were incorporated in a paper-based lateral flow assay that could detect the target with up to 23-fold higher sensitivity within 40-60 minutes.


2010 ◽  
Vol 10 (7) ◽  
pp. 4154-4158 ◽  
Author(s):  
Anurag Jyoti ◽  
Pratibha Pandey ◽  
Surinder Pal Singh ◽  
Swatantra Kumar Jain ◽  
Rishi Shanker

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