An electrochemical aptasensor based on cocoon-like DNA nanostructure signal amplification for the detection of Escherichia coli O157:H7

The Analyst ◽  
2020 ◽  
Vol 145 (22) ◽  
pp. 7340-7348
Author(s):  
Huasong Bai ◽  
Shengjun Bu ◽  
Wensen Liu ◽  
Chengyu Wang ◽  
Zhongyi Li ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Signal Amplification ◽  
Selective Detection ◽  
Escherichia Coli O157 ◽  
Dna Nanostructures ◽  
Electrochemical Aptasensor ◽  
Dna Nanostructure ◽  
Highly Sensitive

We developed an electrochemical aptasensor based on cocoon-like DNA nanostructures as signal tags for highly sensitive and selective detection of Escherichia coli O157:H7.

Rapid and Sensitive Detection of Escherichia coli O157:H7 in Milk and Ground Beef Using Magnetic Bead–Based Immunoassay Coupled with Tyramide Signal Amplification

2014 ◽  
Vol 77 (1) ◽  
pp. 100-105 ◽  
Author(s):  
MUHSIN AYDIN ◽  
GENE P. D. HERZIG ◽  
KWANG CHEOL JEONG ◽  
SAMANTHA DUNIGAN ◽  
PARTH SHAH ◽  
...  
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Food Safety ◽  
Foodborne Pathogens ◽  
Signal Amplification ◽  
Magnetic Bead ◽  
Escherichia Coli O157 ◽  
Tyramide Signal Amplification ◽  
E Coli ◽  
Enrichment Step

Escherichia coli O157:H7 is a major foodborne pathogen that has posed serious problems for food safety and public health. Recent outbreaks and recalls associated with various foods contaminated by E. coli O157:H7 clearly indicate its deleterious effect on food safety. A rapid and sensitive detection assay is needed for this harmful organism to prevent foodborne illnesses and control outbreaks in a timely manner. We developed a magnetic bead–based immunoassay for detection of E. coli O157:H7 (the most well-known Shiga toxigenic E. coli strain) with a 96-well microplate as an assay platform. Immunomagnetic separation (IMS) and tyramide signal amplification were coupled to the assay to increase its sensitivity and specificity. This immunoassay was able to detect E. coli O157:H7 in pure culture with a detection limit of 50 CFU/ml in less than 3 h without an enrichment step. The detection limit was decreased 10-fold to 5 CFU/ml with addition of a 3-h enrichment step. When this assay was tested with other nontarget foodborne pathogens and common enteric bacteria, no cross-reactivity was found. When tested with artificially contaminated ground beef and milk samples, the assay sensitivity decreased two- to fivefold, with detection limits of 250 and 100 CFU/ml, respectively, probably because of the food matrix effect. The assay results also were compared with those of a sandwich-type enzyme-linked immunosorbent assay (ELISA) and an ELISA coupled with IMS; the developed assay was 25 times and 4 times more sensitive than the standard ELISA and the IMS-ELISA, respectively. Tyramide signal amplification combined with IMS can improve sensitivity and specificity for detection of E. coli O157:H7. The developed assay could be easily adapted for other foodborne pathogens and will contribute to improved food safety and public health.

Ratiometric fluorescence and mesoporous structure dual signal amplification for sensitive and selective detection of TNT based on MIP@QD fluorescence sensors

2015 ◽  
Vol 51 (15) ◽  
pp. 3200-3203 ◽  
Author(s):  
Shoufang Xu ◽  
Hongzhi Lu
Keyword(s):  
Signal Amplification ◽  
Mesoporous Structure ◽  
Selective Detection ◽  
Ratiometric Fluorescence ◽  
Fluorescence Sensors ◽  
Highly Sensitive ◽  
Silica Materials ◽  
Mesoporous Silica Materials ◽  
Highly Sensitive Detection ◽  
Dual Signal Amplification

MIP@QD fluorescence sensors combined with ratiometric fluorescence techniques and mesoporous silica materials for highly sensitive detection of TNT.

Highly sensitive and selective detection of miRNA: DNase I-assisted target recycling using DNA probes protected by polydopamine nanospheres

2015 ◽  
Vol 51 (11) ◽  
pp. 2156-2158 ◽  
Author(s):  
Yi Xie ◽  
Xiaoyan Lin ◽  
Yishun Huang ◽  
Rujun Pan ◽  
Zhi Zhu ◽  
...  
Keyword(s):  
Signal Amplification ◽  
Dnase I ◽  
Dna Probes ◽  
Selective Detection ◽  
Protective Properties ◽  
Target Recycling ◽  
Amplification Method ◽  
Highly Sensitive ◽  
Nuclease Digestion

Based on the protective properties of polydopamine nanospheres for DNA probes against nuclease digestion, we have developed a DNase I-assisted target recycling signal amplification method for highly sensitive and selective detection of miRNA.

Carbon nanoparticle-protected aptamers for highly sensitive and selective detection of biomolecules based on nuclease-assisted target recycling signal amplification

2014 ◽  
Vol 50 (57) ◽  
pp. 7646-7648 ◽  
Author(s):  
Xiaoyan Lin ◽  
Liang Cui ◽  
Yishun Huang ◽  
Ya Lin ◽  
Yi Xie ◽  
...  
Keyword(s):  
Signal Amplification ◽  
Carbon Nanoparticles ◽  
Sensitive Detection ◽  
Selective Detection ◽  
Carbon Nanoparticle ◽  
Target Recycling ◽  
Amplification Method ◽  
Highly Sensitive ◽  
Detection Of Biomolecules ◽  
Highly Sensitive Detection

A nuclease-assisted target recycling signal amplification method based on carbon nanoparticles for highly sensitive detection of biomolecules was developed.

Sensitive detection of bisphenol A based on a ratiometric electrochemical aptasensor

2016 ◽  
Vol 94 (5) ◽  
pp. 509-514 ◽  
Author(s):  
Yunqing Liu ◽  
Xia Zhang ◽  
Junshuai Yang ◽  
Erhu Xiong ◽  
Xiaohua Zhang ◽  
...  
Keyword(s):  
Detection Limit ◽  
Bisphenol A ◽  
Selective Detection ◽  
Electrochemical Aptasensor ◽  
Oxidation Peak ◽  
Current Ratio ◽  
Peak Current ◽  
Practical Applications ◽  
Double Stranded Dna ◽  
Highly Sensitive

A new ratiometric electrochemical aptasensor has been developed for highly sensitive and selective detection of bisphenol A (BPA). The double-stranded DNA (dsDNA), consisting of the BPA aptamer (DNA1) and methylene blue (MB)-labeled complementary DNA (cDNA), was immobilized on a gold nanoparticle (AuNP) modified glassy carbon (GC) electrode. In the presence of BPA, the specific BPA–aptamer interaction drove the release of the MB-labeled cDNA from the electrode surface. As a result, the oxidation peak current of MB (IMB) decreased and that of BPA (IBPA) increased. The peak current ratio (IBPA/IMB) of BPA and MB was linear with the concentration of BPA in the range from 1 to 100 pmol/L with a detection limit of 0.6 pmol/L. The detection limit is much lower than that obtained by most of the reported electrochemical methods. On the other hand, the developed aptasensor possesses good selectivity, reproducibility, and stability, and the related sensing structure is very simple, showing promising practical applications in BPA assays.

MicroRNA-induced cascaded and catalytic self-assembly of DNA nanostructures for enzyme-free and sensitive fluorescence detection of microRNA from tumor cells

2016 ◽  
Vol 52 (12) ◽  
pp. 2501-2504 ◽  
Author(s):  
Xue Gong ◽  
Wenjiao Zhou ◽  
Yaqin Chai ◽  
Ruo Yuan ◽  
Yun Xiang
Keyword(s):  
Tumor Cells ◽  
Fluorescence Detection ◽  
Self Assembly ◽  
Signal Amplification ◽  
Sensitive Detection ◽  
Dna Nanostructures ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

MicroRNA-induced self-assembly formation of DNA nanostructures serves as a significant signal amplification platform for the highly sensitive detection of microRNA biomarkers.

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