Ultrasensitive and simple fluorescence biosensor for detection of the mecA gene of Staphylococcus aureus by using an exonuclease III-assisted cascade signal amplification strategy

The Analyst ◽  
2018 ◽  
Vol 143 (23) ◽  
pp. 5670-5675 ◽  
Author(s):  
Qiong Li ◽  
Danhua Zhou ◽  
Jiafeng Pan ◽  
Zhi Liu ◽  
Junhua Chen

An ultrasensitive biosensor was developed for the detection of the mecA gene of Staphylococcus aureus based on the Exo III and G-quadruplex.

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 104
Author(s):  
Fuyuan Zhang ◽  
Linyang Liu ◽  
Shengnan Ni ◽  
Jiankang Deng ◽  
Guo-Jun Liu ◽  
...  

In order to satisfy the need for sensitive detection of Aflatoxin M1 (AFM1), we constructed a simple and signal-on fluorescence aptasensor based on an autocatalytic Exonuclease III (Exo III)-assisted signal amplification strategy. In this sensor, the DNA hybridization on magnetic nanobeads could be triggered by the target AFM1, resulting in the release of a single-stranded DNA to induce an Exo III-assisted signal amplification, in which numerous G-quadruplex structures would be produced and then associated with the fluorescent dye to generate significantly amplified fluorescence signals resulting in the increased sensitivity. Under the optimized conditions, this aptasensor was able to detect AFM1 with a practical detection limit of 9.73 ng kg−1 in milk samples. Furthermore, the prepared sensor was successfully used for detection of AFM1 in the commercially available milk samples with the recovery percentages ranging from 80.13% to 108.67%. Also, the sensor performance was evaluated by the commercial immunoassay kit with satisfactory results.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Yubin Li ◽  
Jiaming Yuan ◽  
Zexi Xu

A C-Ag+-C structure-based fluorescence biosensor with novel combination design of exonuclease III (Exo III) dual-recycling amplification is proposed for the application of silver ions (Ag+) detection. Since oligo-1 involves C-C mismatches, the presence of Ag+ can be captured to form C-Ag+-C base pairs, which results in a double-helix structure with a blunt terminus. The double-helix structure can be cleaved by EXO III to release short mononucleotide fragments (trigger DNA) and Ag+. Released Ag+ can form new bindings with oligo-1, and other trigger DNA can be produced in the digestion cycles. Hybridization with the signal DNA (oligo-2) transforms a trigger DNA into double-stranded DNA with blunt terminus which can be cleaved by Exo III to reproduce the trigger DNA and form guanine- (G-) quadruplex DNA. The trigger DNA returns free to the solution and hybridizes with another signal DNA, which realizes the dual-recycling amplification. The G-quadruplex DNA can be reported by N-methylmesoporphyrin IX (NMM), a specific G-quadruplex DNA fluorochrome. This method allows Ag+ to be determined in the 5 to 1500 pmol/L concentration range, with a 2 pmol/L detection limit, and it has been successfully applied to the detection of Ag+ in real samples.


RSC Advances ◽  
2015 ◽  
Vol 5 (105) ◽  
pp. 86625-86630 ◽  
Author(s):  
Haiyan Zhao ◽  
Lei Wang ◽  
Xingti Liu ◽  
Zhiyue Gao ◽  
Wei Jiang

Schematic illustration of the Exo III-assisted amplification strategy for NAD+ detection.


The Analyst ◽  
2018 ◽  
Vol 143 (18) ◽  
pp. 4267-4272 ◽  
Author(s):  
Biqing Bao ◽  
Yanrui Pan ◽  
Bingbing Gu ◽  
Jia Chen ◽  
Yu Xu ◽  
...  

A ratiometric and cascade amplification strategy that combines the signal amplification and effecitive FRET property of CPEs with the Exo III-assisted target recycling method has been developed for DNA detection.


The Analyst ◽  
2021 ◽  
Author(s):  
Jiafeng Pan ◽  
Dongqin Bao ◽  
Enhu Bao ◽  
Junhua Chen

A simple, highly sensitive biosensor for S. aureus detection is becoming increasingly important in human health and safety. In this work, a hairpin probe-mediated DNA circuit for the detection of...


Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2568
Author(s):  
Yu Chen ◽  
Fuyuan Zhang ◽  
Ruobing Liu ◽  
Minxuan Liu ◽  
Yaxin Sang ◽  
...  

The detection of aflatoxin B1 (AFB1) has recently garnered much attention on the issue of food safety. In this study, a novel and sensitive aptasensor towards AFB1 is proposed using an Exonuclease III (Exo III)-integrated signal amplification strategy. This reported sensing strategy is regulated by aptamer-functionalized nanobeads that can target AFB1; furthermore, complementary DNA (cDNA) strands can lock the immobilized aptamer strands, preventing the signal amplification function of Exo III in the absence of AFB1. The presence of AFB1 triggers the displacement of cDNA, which will then activate the Exo III-integrated signal amplification procedure, resulting in the generation of a guanine (G)-rich sequence to form a G-4/hemin DNAzyme, which can catalyze the substrate of ABTS to produce a green color. Using this method, a practical detection limit of 0.0032 ng/mL and a dynamic range of detection from 0.0032 to 50 ng/mL were obtained. Additionally, the practical application of the established sensing method for AFB1 in complex matrices was demonstrated through recovery experiments. The recovery rate and relative standard deviations (RSD) in three kinds of cereal samples ranged from 93.83% to 111.58%, and 0.82% to 7.20%, respectively, which were comparable with or better than previously reported methods.


The Analyst ◽  
2018 ◽  
Vol 143 (11) ◽  
pp. 2623-2631 ◽  
Author(s):  
Ravikumar A ◽  
Panneerselvam P

We describe a highly sensitive fluorescence biosensor incorporating polydopamine nanotubes (PDNTs) based on the mechanism of exonuclease III (Exo III) assisted signal amplification for the determination of Hg2+ in aqueous solution.


The Analyst ◽  
2021 ◽  
Author(s):  
Chuyan Zhang ◽  
Zewei Luo ◽  
Mengfan Wu ◽  
Wei Ning ◽  
Ziyi Tian ◽  
...  

Sensitive and efficient monitoring of food-borne bacteria is of great importance for food safety control. Herein, a novel biosensor for highly sensitive detection of Staphylococcus aureus (S. aureus) was constructed...


Nanoscale ◽  
2017 ◽  
Vol 9 (42) ◽  
pp. 16149-16153 ◽  
Author(s):  
Chang Yeol Lee ◽  
Hyowon Jang ◽  
Ki Soo Park ◽  
Hyun Gyu Park

A target-triggered catalytic hairpin assembly with a G-quadruplex specific fluorescent binder, NMM, is employed to develop a novel and sensitive RNase H activity assay.


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