scholarly journals An aptasensor for the label-free detection of thrombin based on turn-on fluorescent DNA-templated Cu/Ag nanoclusters

RSC Advances ◽  
2020 ◽  
Vol 10 (58) ◽  
pp. 35374-35380
Author(s):  
Baozhu Zhang ◽  
Chunying Wei

A highly sensitive thrombin aptasensor was constructed based on the alteration of the aptamer conformation induced by the target recognition and the turn-on fluorescence due to the proximity of two darkish DNA-templated copper/silver nanoclusters (DNA-Cu/Ag NCs).

RSC Advances ◽  
2017 ◽  
Vol 7 (89) ◽  
pp. 56289-56295 ◽  
Author(s):  
Baozhu Zhang ◽  
Chunying Wei

A novel turn-on fluorescent biosensor based on C–Hg2+-aptamer-1-DNA-templated silver nanoclusters (Ag NCs) was developed for the quantitative analysis of Hg2+.


2015 ◽  
Vol 7 (19) ◽  
pp. 7989-7994 ◽  
Author(s):  
Hui-Xia Han ◽  
Xue Tian ◽  
Xiang-Juan Kong ◽  
Ru-Qin Yu ◽  
Xia Chu

A label-free and turn-on strategy for H2O2 and glucose detection based on the cleavage of ssDNA by ˙OH and the fluorescence enhancement effect when guanine-rich (G-rich) DNA sequences are in proximity to DNA–silver nanoclusters (DNA–Ag NCs).


2015 ◽  
Vol 51 (37) ◽  
pp. 7958-7961 ◽  
Author(s):  
Ya Wang ◽  
Qianqian Sun ◽  
Linling Zhu ◽  
Junying Zhang ◽  
Fengyang Wang ◽  
...  

A label-free and turn-on strategy based on a triplex molecular beacon for fluorescence melamine recognition with the signaling of Ag NCs was developed.


RSC Advances ◽  
2016 ◽  
Vol 6 (62) ◽  
pp. 57502-57506 ◽  
Author(s):  
Lin Liu ◽  
Qing Li ◽  
Li-Juan Tang ◽  
Ru-Qin Yu ◽  
Jian-Hui Jiang

A hybridization chain reaction (HCR) lightened by DNA-stabilized silver nanoclusters (AgNCs) as a label-free and turn on fluorescence platform for nucleic acid assays.


2014 ◽  
Vol 50 (24) ◽  
pp. 3211-3213 ◽  
Author(s):  
Mengli Yang ◽  
Ying Chen ◽  
Yun Xiang ◽  
Ruo Yuan ◽  
Yaqin Chai

Highly sensitive and label-free detection of thrombin is achieved via a target-induced DNA structure switching strategy and Exo III-assisted recycling amplification.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2889 ◽  
Author(s):  
Ye Teng ◽  
Hisae Tateishi-Karimata ◽  
Takaaki Tsuruoka ◽  
Naoki Sugimoto

Nucleic acid stability and structure, which are crucial to the properties of fluorescent DNA-templated silver nanoclusters (DNA-Ag NCs), significantly change in ionic liquids. In this work, our purpose was to study DNA-Ag NCs in a buffer containing the hydrated ionic liquid of choline dihydrogen phosphate (choline dhp) to improve fluorescence for application in DNA detection. Due to the stabilisation of an i-motif structure by the choline cation, a unique fluorescence emission—that was not seen in an aqueous buffer—was observed in choline dhp and remained stable for more than 30 days. A DNA-Ag NCs probe was designed to have greater fluorescence intensity in choline dhp in the presence of a target DNA. A turn-on sensing platform in choline dhp was built for the detection of the BRCA1 gene, which is related to familial breast and ovarian cancers. This platform showed better sensitivity and selectivity in distinguishing a target sequence from a mutant sequence in choline dhp than in the aqueous buffer. Our study provides new evidence regarding the effects of structure on properties of fluorescent DNA-Ag NCs and expands the applications of fluorescent DNA-Ag NCs in an ionic liquid because of improved sensitivity and selectivity.


2018 ◽  
Vol 71 (12) ◽  
pp. 945
Author(s):  
Xin Fu ◽  
He Zhang ◽  
Jie Zhang ◽  
Shi-Tong Wen ◽  
Xing-Cheng Deng

A highly sensitive and label-free microbead-based ‘turn-on’ assay was developed for the detection of Hg2+ in urine based on the Hg2+-mediated formation of intermolecular split G-quadruplex–hemin DNAzymes. In the presence of Hg2+, T–T mismatches between the two partial cDNA strands were stabilized by a T–Hg2+–T base pair, and can cause the G-rich sequences of the two oligonucleotides to associate to form a split G-quadruplex which is able to bind hemin to form the catalytically active G-quadruplex–hemin DNAzyme. This microbead-based ‘turn-on’ process allows the detection of Hg2+ in urine samples at concentrations as low as 0.5 pM. The relative standard deviation and recovery are 1.2–3.9 and 98.7–103.2%, respectively. The remarkable sensitivity for Hg2+ is mainly attributed to the enhanced mass transport ability that is inherent in homogeneous microbead-based assays. Compared with previous developments of intermolecular split G-quardruplex–hemin DNAzymes for the homogeneous detection of Hg2+ (the limit of detection was 19nM), a signal enhancement of ~1000 times is obtained when such an assay is performed on the surface of microbeads.


2014 ◽  
Vol 6 (15) ◽  
pp. 6082-6087 ◽  
Author(s):  
Hui Ma ◽  
Wei Wei ◽  
Qian Lu ◽  
Zhixin Zhou ◽  
Henan Li ◽  
...  

A label-free DNA biosensor with high sensitivity and selectivity is constructed by using DNA–Ag NCs and Exo III-catalyzed target recycling amplification.


RSC Advances ◽  
2018 ◽  
Vol 8 (72) ◽  
pp. 41464-41471 ◽  
Author(s):  
Jun Peng ◽  
Jian Ling ◽  
Qiu-Lin Wen ◽  
Yu Li ◽  
Qiu-E. Cao ◽  
...  

Single-base mismatched G-rich enhanced DNA-Ag NCs for cyanide detection.


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