A label-free and enzyme-free signal amplification strategy for a sensitive RNase H activity assay

Nanoscale ◽  
2017 ◽  
Vol 9 (42) ◽  
pp. 16149-16153 ◽  
Author(s):  
Chang Yeol Lee ◽  
Hyowon Jang ◽  
Ki Soo Park ◽  
Hyun Gyu Park
Keyword(s):  
Signal Amplification ◽  
Rnase H ◽  
Label Free ◽  
Activity Assay ◽  
G Quadruplex ◽  
Catalytic Hairpin Assembly ◽  
Amplification Strategy

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.

An enzyme-initiated DNAzyme motor for RNase H activity imaging in living cell

2020 ◽  
Vol 56 (4) ◽  
pp. 639-642 ◽  
Author(s):  
Namin Hu ◽  
Yafang Wang ◽  
Chang Liu ◽  
Manman He ◽  
Cunpeng Nie ◽  
...  
Keyword(s):  
Signal Amplification ◽  
Living Cell ◽  
Rnase H ◽  
Amplification Strategy

A signal amplification strategy based on an enzyme-initiated DNAzyme motor for sensitive imaging of RNase H activity in living cell.

scholarly journals A new two-mode fluorescence signal amplification strategy for protease activity assay based on graphene oxide

RSC Advances ◽  
2017 ◽  
Vol 7 (76) ◽  
pp. 47983-47989 ◽  
Author(s):  
Fangfang Wang ◽  
Jie Gao ◽  
Jianwei Zhao ◽  
Wenyue Zhang ◽  
Jie Bai ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Signal Amplification ◽  
Protease Activity ◽  
Fluorescence Signal ◽  
Activity Assay ◽  
Fluorescence Signal Amplification ◽  
Amplification Strategy

A new graphene oxide-based two-mode fluorescence signal amplification strategy for the detection of protease activity has been established.

Trastuzumab (T) detection in serum using signal amplification strategy for non-faradaic impedimetric sensing quartz crystal microbalance (QCM) based on peptide piezo-immunosensors and its role in breast cancer treatment.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e12502-e12502
Author(s):  
Mohammad Muhsin Chisti ◽  
Juan Liu ◽  
Justin Frank Antoni Klamerus ◽  
Ishmael A. Jaiyesimi ◽  
Syeda Hina Batool ◽  
...  
Keyword(s):  
Real Time ◽  
Signal Amplification ◽  
Limit Of Detection ◽  
Cell Immobilization ◽  
Breast Cancers ◽  
Label Free ◽  
Faradaic Impedance ◽  
Free Peptide ◽  
Capacitive Biosensor ◽  
Amplification Strategy

e12502 Background: Her2Neu (H) antigen, expressed on 20% of Breast cancers, is an established target for antibody therapy with T. Immunohistochemistry is still the most widely used technique to detect h level which is time consuming and does not reveal any details of interaction between the molecules. We have developed a new innovative biosensor based novel technique to study real time interaction of h antigens with T using QCM Piezo-immunosensor. This quantitative label free peptide based assay can be used to characterize cell surface antigen, to study antigen- antibody interactions and obtain understanding of mechanisms of resistance. Methods: A label free and reagent free peptide mimotope capacitive biosensor is developed for T quantification based on non-Faradaic readout. The low sensitivity issue of capacitive biosensor was overcome with two innovations: peptide mimotope mixed SAM biointerface and dilution of the testing buffer. Signal amplification was achieved through dilution of the PBS buffer to tune Cdl to dominate the overall capacitance change upon target binding. After 1000 times dilution, limit of detection is lowered 500 times (0.22 µg/mL) and the sensitivity increased 20 times (0.04192 (µg/mL)-1). Results: Binding was very specific. Signal amplification strategy is practical. Further applied to planar electrode for optimizing sensing, response time in less than 1 minute. Conclusions: This is the first report of T detection using electrochemical method based on non-Faradaic impedance. h antigen density and interactions of antigens will help physicians to determine the clinical efficacy and resistance mechanisms to targeted antibodies like T and ado-Trastuzumab.For the first time, we have established a low cost, highly sensitive, fast, synthetic, QCM assay which could be used as a basis for developing a new generation of affinity-based Immunosensor assays. This real time capability and its simplicity of operation are highly suitable for multipurpose studies on living cells including cell immobilization, cytotoxicity of drugs, and the cell action mechanisms

scholarly journals A Label-Free Fluorescent Assay for the Rapid and Sensitive Detection of Adenosine Deaminase Activity and Inhibition

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2441 ◽  
Author(s):  
Xinxing Tang ◽  
Kefeng Wu ◽  
Han Zhao ◽  
Mingjian Chen ◽  
Changbei Ma
Keyword(s):  
Adenosine Deaminase ◽  
High Selectivity ◽  
High Sensitivity ◽  
Rnase H ◽  
Fluorescence Signal ◽  
Label Free ◽  
Fluorescent Assay ◽  
Adenosine Deaminase Activity ◽  
G Quadruplex ◽  
Almost All

Adenosine deaminase (ADA), able to catalyze the irreversible deamination of adenosine into inosine, can be found in almost all tissues and plays an important role in several diseases. In this work, we developed a label-free fluorescence method for the detection of adenosine deaminase activity and inhibition. In the presence of ADA, ATP has been shown to be hydrolyzed. The ATP aptamer was shown to form a G-quadruplex/thioflavin T (ThT) complex with ThT and exhibited an obvious fluorescence signal. However, the ATP aptamer could bind with ATP and exhibited a low fluorescence signal because of the absence of ADA. This assay showed high sensitivity to ADA with a detection limit of 1 U/L based on an SNR of 3 and got a good linear relationship within the range of 1–100 U/L with R2 = 0.9909. The LOD is lower than ADA cutoff value (4 U/L) in the clinical requirement and more sensitive than most of the reported methods. This technique exhibited high selectivity for ADA against hoGG I, UDG, RNase H and λexo. Moreover, this strategy was successfully applied for assaying the inhibition of ADA using erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA) and, as such, demonstrated great potential for the future use in the diagnosis of ADA-relevant diseases, particularly in advanced drug development.

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