scholarly journals DNAzyme-Based Target-Triggered Rolling-Circle Amplification for High Sensitivity Detection of microRNAs

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2017
Author(s):  
Chen Liu ◽  
Jialun Han ◽  
Lujian Zhou ◽  
Jingjing Zhang ◽  
Jie Du
Keyword(s):  
Signal Amplification ◽  
Tumor Suppressor Genes ◽  
Low Cost ◽  
Rolling Circle Amplification ◽  
High Sensitivity ◽  
Rolling Circle ◽  
Highly Sensitive ◽  
And Control ◽  
High Sensitivity Detection

MicroRNAs regulate and control the growth and development of cells and can play the role of oncogenes and tumor suppressor genes, which are involved in the occurrence and development of cancers. In this study, DNA fragments obtained by target-induced rolling-circle amplification were constructed to complement with self-cleaving deoxyribozyme (DNAzyme) and release fluorescence biomolecules. This sensing approach can affect multiple signal amplification permitting fluorescence detection of microRNAs at the pmol L−1 level hence affording a simple, highly sensitive, and selective low cost detection platform.

scholarly journals Recent advances of fluorescent biosensors based on cyclic signal amplification technology in biomedical detection

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Hongke Qu ◽  
Chunmei Fan ◽  
Mingjian Chen ◽  
Xiangyan Zhang ◽  
Qijia Yan ◽  
...  
Keyword(s):  
Signal Amplification ◽  
Low Cost ◽  
Rolling Circle Amplification ◽  
High Sensitivity ◽  
High Specificity ◽  
Detection Methods ◽  
Research Progress ◽  
Rolling Circle ◽  
Displacement Reactions ◽  
Short Time

AbstractThe cyclic signal amplification technology has been widely applied for the ultrasensitive detection of many important biomolecules, such as nucleic acids, proteins, enzymes, adenosine triphosphate (ATP), metal ions, exosome, etc. Due to their low content in the complex biological samples, traditional detection methods are insufficient to satisfy the requirements for monitoring those biomolecules. Therefore, effective and sensitive biosensors based on cyclic signal amplification technology are of great significance for the quick and simple diagnosis and treatment of diseases. Fluorescent biosensor based on cyclic signal amplification technology has become a research hotspot due to its simple operation, low cost, short time, high sensitivity and high specificity. This paper introduces several cyclic amplification methods, such as rolling circle amplification (RCA), strand displacement reactions (SDR) and enzyme-assisted amplification (EAA), and summarizes the research progress of using this technology in the detection of different biomolecules in recent years, in order to provide help for the research of more efficient and sensitive detection methods. Graphical Abstract

A T7 exonuclease-RCA dual amplification system for high-sensitivity and high-selectivity analysis of microRNA

2019 ◽  
Vol 11 (18) ◽  
pp. 2450-2455 ◽  
Author(s):  
Yan Xu ◽  
Yan Li ◽  
Hongkun Zhou ◽  
Xiaoping Mei ◽  
Jieyun Ye ◽  
...  
Keyword(s):  
High Selectivity ◽  
Rolling Circle Amplification ◽  
High Sensitivity ◽  
Selective Detection ◽  
Rolling Circle ◽  
Highly Sensitive ◽  
Amplification System ◽  
Dual Amplification ◽  
T7 Exonuclease

A novel combination of rolling circle amplification and T7 exonuclease-assisted amplification to achieve highly sensitive and selective detection of microRNA molecules was developed.

A functional oligonucleotide probe from an encapsulated silver nanocluster assembled by rolling circle amplification and its application in label-free sensors

RSC Advances ◽  
2016 ◽  
Vol 6 (92) ◽  
pp. 88967-88973 ◽  
Author(s):  
Yuna Guo ◽  
Yu Wang ◽  
Su Liu ◽  
Jinghua Yu ◽  
Qianqian Pei ◽  
...  
Keyword(s):  
Electrochemical Biosensor ◽  
Oligonucleotide Probe ◽  
Low Cost ◽  
Rolling Circle Amplification ◽  
Silver Nanoclusters ◽  
Label Free ◽  
Rolling Circle ◽  
Silver Nanocluster ◽  
E Coli ◽  
Highly Sensitive

A novel label-free, low cost electrochemical biosensor for highly sensitive and selective detection of E. coli has been developed based on rolling circle amplification coupled silver nanoclusters as effective electrochemical probe.

High-sensitivity detection of gold labels by high-angle dark-field STEM imaging

1990 ◽  
Vol 48 (3) ◽  
pp. 892-893 ◽  
Author(s):  
Max T. Otten
Keyword(s):  
High Sensitivity ◽  
Dark Field ◽  
Bright Field ◽  
Backscattered Electron Imaging ◽  
Backscattered Electrons ◽  
Average Atomic Number ◽  
Highly Sensitive ◽  
Backscattered Electron ◽  
Electron Imaging ◽  
High Sensitivity Detection

Labelling of antibodies with small gold probes is a highly sensitive technique for detecting specific molecules in biological tissue. Larger gold probes are usually well visible in TEM or STEM Bright-Field images of unstained specimens. In stained specimens, however, the contrast of the stain is frequently the same as that of the gold labels, making it virtually impossible to identify the labels, especially when smaller gold labels are used to increase the sensitivity of the immunolabelling technique. TEM or STEM Dark-Field images fare no better (Figs. 1a and 2a), again because of the absence of a clear contrast difference between gold labels and stain.Potentially much more useful is backscattered-electron imaging, since this will show differences in average atomic number which are sufficiently large between the metallic gold and the stains normally used. However, for the thin specimens and at high accelerating voltages of the STEM, the yield of backscattered electrons is very small, resulting in a very weak signal. Consequently, the backscattered-electron signal is often too noisy for detecting small labels, even for large spot sizes.

scholarly journals Role of MRI evaluation in acute secondary inability to walk in children

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
K. H. Sedeek ◽  
K. Aboualfotouh ◽  
S. M. Hassanein ◽  
N. M. Osman ◽  
M. H. Shalaby
Keyword(s):  
Transverse Myelitis ◽  
High Sensitivity ◽  
Acute Disseminated Encephalomyelitis ◽  
Limb Weakness ◽  
Non Invasive ◽  
Highly Sensitive ◽  
Common Causes ◽  
Bilateral Lower Limb ◽  
Severity Of The Disease

Abstract Background Acute bilateral lower limb weakness is a common problem in children which necessitates a rapid method for diagnosis. MRI is a non-invasive imaging technique that produces high-quality images of the internal structure of the brain and spinal cord. Results MRI was very helpful in reaching rapid and prompt diagnosis in children with acute inability to walk. Acute disseminated encephalomyelitis (ADEM), Guillain–Barré syndrome (GBS), and acute transverse myelitis (ATM) were the most common causes in our study. MRI proved to be of high sensitivity in detecting the lesions and reaching the diagnosis in ADEM and GBS; however, there was no significant relation between the lesions’ size, enhancement pattern, and severity of the disease or prognosis, yet in ATM the site of the lesion and number of cord segment affection were significantly related to the severity of the disease and prognosis. Conclusion MRI is a quick tool to reach the diagnosis of children with acute secondary inability to walk, and to eliminate other differential diagnosis which is essential for proper treatment and rapid full recovery. It is highly sensitive in detecting the lesions, their site and size.

scholarly journals MiRNA Detection Using a Rolling Circle Amplification and RNA-Cutting Allosteric Deoxyribozyme Dual Signal Amplification Strategy

Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 222
Author(s):  
Chenxin Fang ◽  
Ping Ouyang ◽  
Yuxing Yang ◽  
Yang Qing ◽  
Jialun Han ◽  
...  
Keyword(s):  
Signal Amplification ◽  
Rolling Circle Amplification ◽  
Padlock Probe ◽  
Rolling Circle ◽  
Sensing Platform ◽  
Mirna Detection ◽  
Substrate Cleavage ◽  
Amplification Strategy ◽  
Circular Template ◽  
Dual Signal Amplification

A microRNA (miRNA) detection platform composed of a rolling circle amplification (RCA) system and an allosteric deoxyribozyme system is proposed, which can detect miRNA-21 rapidly and efficiently. Padlock probe hybridization with the target miRNA is achieved through complementary base pairing and the padlock probe forms a closed circular template under the action of ligase; this circular template results in RCA. In the presence of DNA polymerase, RCA proceeds and a long chain with numerous repeating units is formed. In the presence of single-stranded DNA (H1 and H2), multi-component nucleic acid enzymes (MNAzymes) are formed that have the ability to cleave substrates. Finally, substrates containing fluorescent and quenching groups and magnesium ions are added to the system to activate the MNAzyme and the substrate cleavage reaction, thus achieving fluorescence intensity amplification. The RCA–MNAzyme system has dual signal amplification and presents a sensing platform that demonstrates broad prospects in the analysis and detection of nucleic acids.

Highly sensitive detection of Cr(vi) in groundwater by bimetallic NiFe nanoparticles

2017 ◽  
Vol 9 (6) ◽  
pp. 1031-1037 ◽  
Author(s):  
Jingtao Liu ◽  
Yu Ding ◽  
Lifei Ji ◽  
Xin Zhang ◽  
Fengchun Yang ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Hexavalent Chromium ◽  
Low Cost ◽  
High Sensitivity ◽  
Sensitive Detection ◽  
Toxic Heavy Metal ◽  
Metal Pollutants ◽  
Highly Sensitive ◽  
Highly Sensitive Detection ◽  
Heavy Metal Pollutants

Hexavalent chromium (Cr(vi)) is one of the most toxic heavy metal pollutants in groundwater, and thus the detection of Cr(vi) with high sensitivity, accuracy, and simplicity and low cost is of great importance.

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