A novel signal amplification strategy for highly specific and nonenzymatic isothermal electrochemiluminescence detection of tumour markers

2020 ◽  
Vol 12 (7) ◽  
pp. 938-942 ◽  
Author(s):  
Yan Liu ◽  
Xin Guo ◽  
Zhijin Fan ◽  
Yuhui Liao ◽  
Ying Yu ◽  
...  
Keyword(s):  
Signal Amplification ◽  
Limit Of Detection ◽  
Tumour Markers ◽  
Linear Dna ◽  
Amplification Strategy

A signal amplification strategy for highly specific and nonenzymatic isothermal electrochemiluminescence detection of microRNA was developed. The limit of detection was as low as 4 fmol, which was superior to that for the reported linear DNA method.

scholarly journals A novel electrochemical aptasensor for fumonisin B1 determination using DNA and exonuclease-I as signal amplification strategy

BMC Chemistry ◽  
2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Min Wei ◽  
Fei Zhao ◽  
Shuo Feng ◽  
Huali Jin
Keyword(s):  
Incubation Time ◽  
Electrode Surface ◽  
Signal Amplification ◽  
Limit Of Detection ◽  
Fumonisin B1 ◽  
Electrochemical Aptasensor ◽  
Experimental Conditions ◽  
Exonuclease I ◽  
Double Stranded Dna ◽  
Amplification Strategy

Abstract In this work, using DNA and exonuclease-I (Exo-I) as signal amplification strategy, a novel and facile electrochemical aptasensor was constructed for fumonisin B1 (FB1) detection. The G-rich complementary DNA (cDNA) was immobilized onto the electrode surface. Then, aptamer of FB1 was hybridized with cDNA to form double-stranded DNA. In the absence of FB1, double-stranded DNA and G-rich cDNA on the electrode surface promoted effectively methylene blue (MB) enrichment and amplified the initial electrochemical response. In the presence of FB1, the combination of aptamer and FB1 led to the release of aptamer from the electrode surface and the expose of 3′ end of single-stranded cDNA. When Exo-I was added onto the electrode surface, the single-stranded cDNA was degraded in the 3′–5′ direction. The decrease of double-stranded DNA and G-rich cDNA resulted in the less access of MB to the electrode surface, which decreased the electrochemical signal. The experimental conditions including incubation time of FB1, the amount of Exo-I and incubation time of Exo-I were optimized. Under the optimal conditions, the linear relationship between the change of peak current and the logarithmic concentration of FB1 was observed in the range of 1.0 × 10−3–1000 ng mL−1 with a low limit of detection of 0.15 pg mL−1. The experimental results showed that the prepared aptasensor had acceptable specificity, reproducibility, repeatability and stability. Therefore, this proposed aptasensor has a potential application in the food safety detection.

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 novel electrochemical aptasensor for fumonisin B1 determination using DNA and exonuclease-I as signal amplification strategy

2019 ◽  
Author(s):  
Min Wei ◽  
Fei Zhao ◽  
Shuo Feng ◽  
Huali Jin
Keyword(s):  
Incubation Time ◽  
Electrode Surface ◽  
Signal Amplification ◽  
Limit Of Detection ◽  
Fumonisin B1 ◽  
Electrochemical Aptasensor ◽  
Experimental Conditions ◽  
Exonuclease I ◽  
Double Stranded Dna ◽  
Amplification Strategy

Abstract In this work, using DNA and exonuclease-I (Exo-I) as signal amplification strategy, a novel and facile electrochemical aptasensor was constructed for fumonisin B1 (FB1) detection. The G-rich complementary DNA (cDNA) was immobilized onto the electrode surface. Then, aptamer of FB1 was hybridized with cDNA to form double-stranded DNA. In the absence of FB1, double-stranded DNA and G-rich cDNA on the electrode surface promoted effectively methylene blue (MB) enrichment and amplified the initial electrochemical response. In the presence of FB1, the combination of aptamer and FB1 led to the release of aptamer from the electrode surface and the expose of 3' end of single-stranded cDNA. When Exo-I was added onto the electrode surface, the single-stranded cDNA was degraded in the 3’-5’ direction. The decrease of double-stranded DNA and G-rich cDNA resulted in the less access of MB to the electrode surface, which decreased the electrochemical signal. The experimental conditions including incubation time of FB1, the amount of Exo-I and incubation time of Exo-I were optimized. Under the optimal conditions, the linear relationship between the change of peak current and the logarithmic concentration of FB1 was observed in the range of 1.0×10-3-1000ng·mL−1 with a low limit of detection of 0.15 pg·mL−1. The experimental results showed that the prepared aptasensor had acceptable specificity, reproducibility, repeatability and stability. Therefore, this proposed aptasensor has a potential application in the food safety detection.

scholarly journals A novel electrochemical aptasensor for fumonisin B1 determination using DNA and exonuclease-I as signal amplification strategy

2019 ◽  
Author(s):  
Min Wei ◽  
Fei Zhao ◽  
Shuo Feng ◽  
Huali Jin
Keyword(s):  
Incubation Time ◽  
Electrode Surface ◽  
Signal Amplification ◽  
Limit Of Detection ◽  
Fumonisin B1 ◽  
Electrochemical Aptasensor ◽  
Experimental Conditions ◽  
Exonuclease I ◽  
Double Stranded Dna ◽  
Amplification Strategy

Abstract In this work, using DNA and exonuclease-I (Exo-I) as signal amplification strategy, a novel and facile electrochemical aptasensor was constructed for fumonisin B1 (FB1) detection. The G-rich complementary DNA (cDNA) was immobilized onto the electrode surface. Then, aptamer of FB1 was hybridized with cDNA to form double-stranded DNA. In the absence of FB1, double-stranded DNA and G-rich cDNA on the electrode surface promoted effectively methylene blue (MB) enrichment and amplified the initial electrochemical response. In the presence of FB1, the combination of aptamer and FB1 led to the release of aptamer from the electrode surface and the expose of 3' end of single-stranded cDNA. When Exo-I was added onto the electrode surface, the single-stranded cDNA was degraded in the 3’-5’ direction. The decrease of double-stranded DNA and G-rich cDNA resulted in the less access of MB to the electrode surface, which decreased the electrochemical signal. The experimental conditions including incubation time of FB1, the amount of Exo-I and incubation time of Exo-I were optimized. Under the optimal conditions, the linear relationship between the change of peak current and the logarithmic concentration of FB1 was observed in the range of 1.0×10-3-1000ng·mL−1 with a low limit of detection of 0.15 pg·mL−1. The experimental results showed that the prepared aptasensor had acceptable specificity, reproducibility, repeatability and stability. Therefore, this proposed aptasensor has a potential application in the food safety detection.

scholarly journals CRISPR/Cas13a signal amplification linked immunosorbent assay (CLISA)

2019 ◽  
Author(s):  
Qian Chen ◽  
Tian Tian ◽  
Erhu Xiong ◽  
Po Wang ◽  
Xiaoming Zhou
Keyword(s):  
Immunosorbent Assay ◽  
Signal Amplification ◽  
Limit Of Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Inflammatory Factor ◽  
Early Diagnosis Of Cancer ◽  
Low Concentrations ◽  
Conventional Elisa ◽  
Amplification Strategy ◽  
Endothelial Growth Factor

ABSTRACTThe enzyme-linked immunosorbent assay (ELISA) is a basic technique used in analytical and clinical investigations. However, conventional ELISA is still not sensitive enough to detect ultra-low concentrations of biomarkers for the early diagnosis of cancer, cardiovascular risk, neurological disorders, and infectious diseases. Herein we show a mechanism utilizing the CRISPR/Cas13a-based signal export amplification strategy, which double-amplifies the output signal by T7 RNA polymerase transcription and CRISPR/Cas13a collateral cleavage activity. This process is termed the CRISPR/Cas13a signal amplification linked immunosorbent assay (CLISA). The proposed method was validated by detecting an inflammatory factor, human interleukin-6 (human IL-6), and a tumor marker, human vascular endothelial growth factor (human VEGF), which achieved limit of detection (LOD) values of 45.81 fg/mL (2.29 fM) and 32.27 fg/m (0.81 fM), respectively, demonstrating that CLISA is at least 102-fold more sensitive than conventional ELISA.

scholarly journals A novel electrochemical aptasensor for fumonisin B1 determination using DNA and exonuclease-I as signal amplification strategy

2019 ◽  
Author(s):  
Min Wei ◽  
Fei Zhao ◽  
Shuo Feng ◽  
Huali Jin
Keyword(s):  
Incubation Time ◽  
Electrode Surface ◽  
Signal Amplification ◽  
Limit Of Detection ◽  
Fumonisin B1 ◽  
Electrochemical Aptasensor ◽  
Experimental Conditions ◽  
Exonuclease I ◽  
Double Stranded Dna ◽  
Amplification Strategy

Abstract In this work, using DNA and exonuclease-I (Exo-I) as signal amplification strategy, a novel and facile electrochemical aptasensor was constructed for fumonisin B1 (FB1) detection. The G-rich complementary DNA (cDNA) was immobilized onto the electrode surface. Then, aptamer of FB1 was hybridized with cDNA to form double-stranded DNA. In the absence of FB1, double-stranded DNA and G-rich cDNA on the electrode surface promoted effectively methylene blue (MB) enrichment and amplified the initial electrochemical response. In the presence of FB1, the combination of aptamer and FB1 led to the release of aptamer from the electrode surface and the expose of 3' end of single-stranded cDNA. When Exo-I was added onto the electrode surface, the single-stranded cDNA was degraded in the 3’-5’ direction. The decrease of double-stranded DNA and G-rich cDNA resulted in the less access of MB to the electrode surface, which decreased the electrochemical signal. The experimental conditions including incubation time of FB1, the amount of Exo-I and incubation time of Exo-I were optimized. Under the optimal conditions, the linear relationship between the change of peak current and the logarithmic concentration of FB1 was observed in the range of 1.0×10-3-1000ng·mL−1 with a low limit of detection of 0.15 pg·mL−1. The experimental results showed that the prepared aptasensor had acceptable specificity, reproducibility, repeatability and stability. Therefore, this proposed aptasensor has a potential application in the food safety detection.

scholarly journals A novel electrochemical aptasensor for fumonisin B1 determination using DNA and exonuclease-I as signal amplification strategy

2019 ◽  
Author(s):  
Min Wei ◽  
Fei Zhao ◽  
Shuo Feng ◽  
Huali Jin
Keyword(s):  
Incubation Time ◽  
Electrode Surface ◽  
Signal Amplification ◽  
Limit Of Detection ◽  
Fumonisin B1 ◽  
Electrochemical Aptasensor ◽  
Experimental Conditions ◽  
Exonuclease I ◽  
Double Stranded Dna ◽  
Amplification Strategy

Abstract In this work, using DNA and exonuclease-I (Exo-I) as signal amplification strategy, a novel and facile electrochemical aptasensor was constructed for fumonisin B1 (FB1) detection. The G-rich complementary DNA (cDNA) was immobilized onto the electrode surface. Then, aptamer of FB1 was hybridized with cDNA to form double-stranded DNA. In the absence of FB1, double-stranded DNA and G-rich cDNA on the electrode surface promoted effectively methylene blue (MB) enrichment and amplified the initial electrochemical response. In the presence of FB1, the combination of aptamer and FB1 led to the release of aptamer from the electrode surface and the expose of 3' end of single-stranded cDNA. When Exo-I was added onto the electrode surface, the single-stranded cDNA was degraded in the 3’-5’ direction. The decrease of double-stranded DNA and G-rich cDNA resulted in the less access of MB to the electrode surface, which decreased the electrochemical signal. The experimental conditions including incubation time of FB1, the amount of Exo-I and incubation time of Exo-I were optimized. Under the optimal conditions, the linear relationship between the change of peak current and the logarithmic concentration of FB1 was observed in the range of 1.0×10-3-1000ng·mL−1 with a low limit of detection of 0.15 pg·mL−1. The experimental results showed that the prepared aptasensor had acceptable specificity, reproducibility, repeatability and stability. Therefore, this proposed aptasensor has a potential application in the food safety detection.

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.

scholarly journals Signal Amplification in an Optical and Dielectric Biosensor Employing Liquid Crystal-Photopolymer Composite as the Sensing Medium

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 81
Author(s):  
Hassanein Shaban ◽  
Shih-Chun Yen ◽  
Mon-Juan Lee ◽  
Wei Lee
Keyword(s):  
Dielectric Constant ◽  
Liquid Crystal ◽  
Uv Irradiation ◽  
Signal Amplification ◽  
Limit Of Detection ◽  
Optical Signal ◽  
Uv Exposure ◽  
Dielectric Anisotropy ◽  
Optical Texture ◽  
Potential Development

An optical and dielectric biosensor based on a liquid crystal (LC)–photopolymer composite was established in this study for the detection and quantitation of bovine serum albumin (BSA). When the nematic LC E7 was doped with 4-wt.% NOA65, a photo-curable prepolymer, and photopolymerized by UV irradiation at 20 mW/cm2 for 300 s, the limit of detection determined by image analysis of the LC optical texture and dielectric spectroscopic measurements was 3400 and 88 pg/mL for BSA, respectively, which were lower than those detected with E7 alone (10 μg/mL BSA). The photopolymerized NOA65, but not the prepolymer prior to UV exposure, contributed to the enhanced optical signal, and UV irradiation of pristine E7 in the absence of NOA65 had no effect on the optical texture. The effective tilt angle θ, calculated from the real-part dielectric constant ε’, decreased with increasing BSA concentration, providing strong evidence for the correlation of photopolymerized NOA65 to the intensified disruption in the vertically oriented LC molecules to enhance the optical and dielectric signals of BSA. The optical and dielectric anisotropy of LCs and the photo-curable dopant facilitate novel quantitative and signal amplification approaches to potential development of LC-based biosensors.

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