scholarly journals In Vivo Two-Way Redox Cycling System for Independent Duplexed Electrochemical Signal Amplification

2019 ◽  
Vol 91 (8) ◽  
pp. 4939-4942 ◽  
Author(s):  
Yuan Yang ◽  
Yang-Yang Yu ◽  
Yu-Tong Shi ◽  
Jamile Mohammadi Moradian ◽  
Yang-Chun Yong
Keyword(s):  
Signal Amplification ◽  
Redox Cycling ◽  
Electrochemical Signal ◽  
Cycling System

Scaling up an electrochemical signal with a catalytic hairpin assembly coupling nanocatalyst label for DNA detection

2015 ◽  
Vol 51 (33) ◽  
pp. 7100-7103 ◽  
Author(s):  
Xu Hun ◽  
Guoliang Xie ◽  
Xiliang Luo
Keyword(s):  
Detection Limit ◽  
Electrochemical Detection ◽  
Signal Amplification ◽  
Dna Detection ◽  
Scaling Up ◽  
Redox Cycling ◽  
New Strategy ◽  
Electrochemical Signal ◽  
Catalytic Hairpin Assembly

A new strategy for the electrochemical detection of DNA based on catalytic hairpin assembly combined with nanocatalyst label-based redox cycling reaction signal amplification. A superior detection limit of 0.3 aM toward DNA was achieved.

scholarly journals Metal Nanoparticle and Quantum Dot Tags for Signal Amplification in Electrochemical Immunosensors for Biomarker Detection

Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 85
Author(s):  
Anton Popov ◽  
Benediktas Brasiunas ◽  
Asta Kausaite-Minkstimiene ◽  
Almira Ramanaviciene
Keyword(s):  
Signal Amplification ◽  
Electrochemical Immunosensor ◽  
Metal Nanoparticle ◽  
Biomarker Detection ◽  
Analytical Instruments ◽  
Electrochemical Immunosensors ◽  
Highly Sensitive ◽  
Recent Developments ◽  
Electrochemical Signal ◽  
Detection Of Biomarkers

With the increasing importance of healthcare and clinical diagnosis, as well as the growing demand for highly sensitive analytical instruments, immunosensors have received considerable attention. In this review, electrochemical immunosensor signal amplification strategies using metal nanoparticles (MNPs) and quantum dots (Qdots) as tags are overviewed, focusing on recent developments in the ultrasensitive detection of biomarkers. MNPs and Qdots can be used separately or in combination with other nanostructures, while performing the function of nanocarriers, electroactive labels, or catalysts. Thus, different functions of MNPs and Qdots as well as recent advances in electrochemical signal amplification are discussed. Additionally, the methods most often used for antibody immobilization on nanoparticles, immunoassay formats, and electrochemical methods for indirect biomarker detection are overviewed.

scholarly journals Photoelectrochemical-Chemical-Chemical Redox Cycling for Advanced Signal Amplification: Proof-of-Concept Toward Ultrasensitive Photoelectrochemical Bioanalysis

2018 ◽  
Vol 90 (21) ◽  
pp. 12347-12351 ◽  
Author(s):  
Bing Wang ◽  
Li-Ping Mei ◽  
Yan Ma ◽  
Yi-Tong Xu ◽  
Shu-Wei Ren ◽  
...  
Keyword(s):  
Signal Amplification ◽  
Redox Cycling ◽  
Proof Of Concept

scholarly journals DNA/RNA Electrochemical Biosensing Devices a Future Replacement of PCR Methods for a Fast Epidemic Containment

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4648 ◽  
Author(s):  
Manikandan Santhanam ◽  
Itay Algov ◽  
Lital Alfonta
Keyword(s):  
Signal Amplification ◽  
Nucleic Acid Hybridization ◽  
Diagnostic Tools ◽  
Testing Method ◽  
Reverse Transcription Pcr ◽  
Electrochemical Biosensing ◽  
Low Copy Number ◽  
Rna Sensors ◽  
Electrochemical Signal ◽  
Sensitive Testing

Pandemics require a fast and immediate response to contain potential infectious carriers. In the recent 2020 Covid-19 worldwide pandemic, authorities all around the world have failed to identify potential carriers and contain it on time. Hence, a rapid and very sensitive testing method is required. Current diagnostic tools, reverse transcription PCR (RT-PCR) and real-time PCR (qPCR), have its pitfalls for quick pandemic containment such as the requirement for specialized professionals and instrumentation. Versatile electrochemical DNA/RNA sensors are a promising technological alternative for PCR based diagnosis. In an electrochemical DNA sensor, a nucleic acid hybridization event is converted into a quantifiable electrochemical signal. A critical challenge of electrochemical DNA sensors is sensitive detection of a low copy number of DNA/RNA in samples such as is the case for early onset of a disease. Signal amplification approaches are an important tool to overcome this sensitivity issue. In this review, the authors discuss the most recent signal amplification strategies employed in the electrochemical DNA/RNA diagnosis of pathogens.

scholarly journals Endogenous Carbon Monoxide Signaling Modulates Mitochondrial Function and Intracellular Glucose Utilization: Impact of the Heme Oxygenase Substrate Hemin

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 652 ◽  
Author(s):  
David Stucki ◽  
Julia Steinhausen ◽  
Philipp Westhoff ◽  
Heide Krahl ◽  
Dominik Brilhaus ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Glucose Metabolism ◽  
Respiratory Chain ◽  
Heme Oxygenase ◽  
Antioxidant Defense ◽  
Redox Cycling ◽  
Short Term ◽  
Heme Oxygenases ◽  
Cycling System

Stress-inducible heme oxygenase-1 (HO-1) catalyzes the oxidative cleavage of heme yielding biliverdin, ferrous iron, and carbon monoxide (CO). Heme oxygenase activity has been attributed to antioxidant defense via the redox cycling system of biliverdin and bilirubin. There is increasing evidence that CO is a gaseous signaling molecule and plays a role in the regulation of energy metabolism. Inhibitory effects of CO on the respiratory chain are well established, but the implication of such a process on the cellular stress response is not well understood. By means of extracellular flux analyses and isotopic tracing, we studied the effects of CO, either released from the CO donor CORM-401 or endogenously produced by heme oxygenases, on the respiratory chain and glucose metabolism. CORM-401 was thereby used as a tool to mimic endogenous CO production by heme oxygenases. In the long term (>60 min), CORM-401-derived CO exposure inhibited mitochondrial respiration, which was compensated by increased glycolysis accompanied by a loss of the ATP production rate and an increase in proton leakage. This effect pattern was likewise observed after endogenous CO production by heme oxygenases. However, in the present setting, these effects were only observed when sufficient substrate for heme oxygenases (hemin) was provided. Modulation of the HO-1 protein level was less important. The long-term influence of CO on glucose metabolism via glycolysis was preceded by a short-term response (<30 min) of the cells to CO. Stable isotope-labeling experiments and metabolic flux analysis revealed a short-term shift of glucose consumption from glycolysis to the pentose phosphate pathway (PPP) along with an increase in reactive oxygen species (ROS) generation. Overall, we suggest that signaling by endogenous CO stimulates the rapid formation of reduction equivalents (NADPH) via the PPP, and plays an additional role in antioxidant defense, e.g., via feed-forward stimulation of the bilirubin/biliverdin redox cycling system.

scholarly journals Oligomerization of Paramagnetic Substrates Result in Signal Amplification and Can be Used for MR Imaging of Molecular Targets

2002 ◽  
Vol 1 (1) ◽  
pp. 153535002002000 ◽  
Author(s):  
Alexei Bogdanov ◽  
Lars Matuszewski ◽  
Christoph Bremer ◽  
Alexander Petrovsky ◽  
Ralph Weissleder
Keyword(s):  
Signal Amplification ◽  
Imaging Modality ◽  
Functional Characterization ◽  
Molecular Targets ◽  
Transgenic Animals ◽  
Rotational Correlation Time ◽  
In Vivo Detection ◽  
Noninvasive Imaging Modality ◽  
Magnetic Resonance Imaging Mri

Magnetic resonance imaging (MRI) has evolved into a sophisticated, noninvasive imaging modality capable of high-resolution anatomical and functional characterization of transgenic animals. To expand the capabilities MRI, we have developed a novel MR signal amplification (MRamp) strategy based on enzyme-mediated polymerization of paramagnetic substrates into oligomers of higher magnetic relaxivity. The substrates consist of chelated gadolinium covalently bound to phenols, which then serve as electron donors during enzymatic hydrogen peroxide reduction by peroxidase. The converted monomers undergo rapid condensation into paramagnetic oligomers leading to a threefold increase in atomic relaxivity ( R1/Gd). The observed relaxivity changes are largely due to an increase in the rotational correlation time τr of the lanthanide. Three applications of the developed system are demonstrated: (1) imaging of nanomolar amounts of an oxidoreductase (peroxidase); (2) detection of a model ligand using an enzyme-linked immunoadsorbent assay format; and (3) imaging of E-selectin on the surface of endothelial cells probed for with an anti-E-selectin – peroxidase conjugate. The development of “enzyme sensing” probes is expected to have utility for a number of applications including in vivo detection of specific molecular targets. One particular advantage of the MRamp technique is that the same paramagnetic substrate can be potentially used to identify different molecular targets by attaching enzymes to various antibodies or other target-seeking molecules.

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