scholarly journals Comparison of DNAzyme activity for the development of an immobilized heme sensor

MRS Advances ◽  
2018 ◽  
Vol 3 (26) ◽  
pp. 1491-1496
Author(s):  
Natalie Hughes ◽  
Nancy Nguyen ◽  
Deanna-Kaye Daley ◽  
Justin Grennell ◽  
Amira Gee ◽  
...  
Keyword(s):  
Self Assembly ◽  
Point Of Care ◽  
Label Free ◽  
Detection Range ◽  
Chemical Complexity ◽  
Detection Strategy ◽  
Detection Approach ◽  
Label Free Detection ◽  
G Quadruplex ◽  
Care Systems

ABSTRACTPoint-of-care systems require highly sensitive, quantitative and selective detection platforms for the real-time multiplexed monitoring of target analytes. To ensure facile development of a sensor, it is preferable for the detection assay to have minimal chemical complexity, contain no wash steps and provide a wide and easily adaptable detection range for multiple targets. Current studies involve label-free detection strategy for relevant clinical molecules such as heme using G-quadruplex based self-assembly. We have explored the measurement of binding and kinetic parameters of various G-quadruplex/heme complexes which are able to self-associate to form a DNAzyme with peroxidase mimicking capabilities and are critical to nucleic acid research. The detection strategy includes immobilizing the G-quadruplex sequences within a polymer matrix to provide a self-assembly based detection approach for heme that could be translated towards other clinically relevant targets.

Direct Label Free Detection of Orchid Virus Using a Micro/Nano Hybrid Structured Biosensor

2019 ◽  
Author(s):  
Wei-Jhen Wang ◽  
Chia-Hwa Lee ◽  
Chin-Wen Li ◽  
Stephen Liao ◽  
Fuh-Jyh Jan ◽  
...  
Keyword(s):  
Label Free ◽  
Self Assembled Monolayer ◽  
Detection Range ◽  
Elisa Kit ◽  
Detection Approach ◽  
Linear Detection ◽  
Label Free Detection ◽  
Semiconductor Fabrication ◽  
Direct Label ◽  
Higher Sensitivity

Abstract In this study, a label-free detection approach for effective detection of the odontoglossum ringspot virus (ORSV) infected orchids has been developed. We used semiconductor fabrication process to fabricate 1,810 micro/nano hybrid structured sensing electrodes on a 8 inch reclaimed wafer. The self-assembled monolayer (SAM) process was then employed to sequentially modify the electrode surface with 11-mercaptoundecanoic acid (11-MUA), 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC)/ N-hydroxysuccinimide (NHS), anti-ORSV, and ORSV. EIS was conducted for the ORSV concentration detection. Experimental results demonstrated that the ORSV concentration in a virus infected orchid leaf could be effectively detected. When compared with the ELISA kit, our device possesses a wider linear detection range (0.5–50,000 ng/mL) and a higher sensitivity. The specificity of our device on ORSV detection was also confirmed. Our sensing device retains advantages, such as label-free, lower amounts of the antibody and target sample required, low detection time, and a wider linear detection range. Those results imply the feasibility of our sensing device in field applications.

scholarly journals Label-Free Electrochemical Sensor for Rapid Bacterial Pathogen Detection Using Vancomycin-Modified Highly Branched Polymers

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1872
Author(s):  
Holger Schulze ◽  
Harry Wilson ◽  
Ines Cara ◽  
Steven Carter ◽  
Edward N. Dyson ◽  
...  
Keyword(s):  
Pathogen Detection ◽  
Electrochemical Impedance ◽  
Point Of Care ◽  
Branched Polymers ◽  
Label Free ◽  
Conformation Change ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Staphylococcus Carnosus ◽  
Label Free Detection

Rapid point of care tests for bacterial infection diagnosis are of great importance to reduce the misuse of antibiotics and burden of antimicrobial resistance. Here, we have successfully combined a new class of non-biological binder molecules with electrochemical impedance spectroscopy (EIS)-based sensor detection for direct, label-free detection of Gram-positive bacteria making use of the specific coil-to-globule conformation change of the vancomycin-modified highly branched polymers immobilized on the surface of gold screen-printed electrodes upon binding to Gram-positive bacteria. Staphylococcus carnosus was detected after just 20 min incubation of the sample solution with the polymer-functionalized electrodes. The polymer conformation change was quantified with two simple 1 min EIS tests before and after incubation with the sample. Tests revealed a concentration dependent signal change within an OD600 range of Staphylococcus carnosus from 0.002 to 0.1 and a clear discrimination between Gram-positive Staphylococcus carnosus and Gram-negative Escherichia coli bacteria. This exhibits a clear advancement in terms of simplified test complexity compared to existing bacteria detection tests. In addition, the polymer-functionalized electrodes showed good storage and operational stability.

scholarly journals A sandwich-like strategy for the label-free detection of oligonucleotides by surface plasmon fluorescence spectroscopy (SPFS)

The Analyst ◽  
2016 ◽  
Vol 141 (20) ◽  
pp. 5784-5791 ◽  
Author(s):  
Qiang Su ◽  
Gilbert Nöll
Keyword(s):  
Fluorescence Spectroscopy ◽  
Surface Plasmon ◽  
Molecular Beacons ◽  
Label Free ◽  
Background Fluorescence ◽  
Detection Strategy ◽  
Cutting Surface ◽  
Label Free Detection ◽  
Lower Background

Cutting surface-bound optical molecular beacons results in a sandwich-like detection strategy with lower background fluorescence.

Ultrasensitive WSe2 field-effect transistor-based biosensor for label-free detection of cancer in point-of-care applications

2D Materials ◽  
2021 ◽  
Author(s):  
Mohammad Mosarof Hossain ◽  
Babar Shabbir ◽  
Yingjie Wu ◽  
Wenzhi Yu ◽  
Vaishnavi Krishnamurthi ◽  
...  
Keyword(s):  
Field Effect ◽  
Field Effect Transistor ◽  
Point Of Care ◽  
Label Free ◽  
Label Free Detection ◽  
Effect Transistor

scholarly journals Field-Effect Sensors for Virus Detection: From Ebola to SARS-CoV-2 and Plant Viral Enhancers

2020 ◽  
Vol 11 ◽  
Author(s):  
Arshak Poghossian ◽  
Melanie Jablonski ◽  
Denise Molinnus ◽  
Christina Wege ◽  
Michael J. Schöning
Keyword(s):  
Field Effect ◽  
Point Of Care ◽  
Virus Detection ◽  
Fast Response ◽  
Plant Viruses ◽  
Clinical Samples ◽  
Label Free ◽  
Label Free Detection ◽  
Field Effect Devices ◽  
Long Time

Coronavirus disease 2019 (COVID-19) is a novel human infectious disease provoked by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Currently, no specific vaccines or drugs against COVID-19 are available. Therefore, early diagnosis and treatment are essential in order to slow the virus spread and to contain the disease outbreak. Hence, new diagnostic tests and devices for virus detection in clinical samples that are faster, more accurate and reliable, easier and cost-efficient than existing ones are needed. Due to the small sizes, fast response time, label-free operation without the need for expensive and time-consuming labeling steps, the possibility of real-time and multiplexed measurements, robustness and portability (point-of-care and on-site testing), biosensors based on semiconductor field-effect devices (FEDs) are one of the most attractive platforms for an electrical detection of charged biomolecules and bioparticles by their intrinsic charge. In this review, recent advances and key developments in the field of label-free detection of viruses (including plant viruses) with various types of FEDs are presented. In recent years, however, certain plant viruses have also attracted additional interest for biosensor layouts: Their repetitive protein subunits arranged at nanometric spacing can be employed for coupling functional molecules. If used as adapters on sensor chip surfaces, they allow an efficient immobilization of analyte-specific recognition and detector elements such as antibodies and enzymes at highest surface densities. The display on plant viral bionanoparticles may also lead to long-time stabilization of sensor molecules upon repeated uses and has the potential to increase sensor performance substantially, compared to conventional layouts. This has been demonstrated in different proof-of-concept biosensor devices. Therefore, richly available plant viral particles, non-pathogenic for animals or humans, might gain novel importance if applied in receptor layers of FEDs. These perspectives are explained and discussed with regard to future detection strategies for COVID-19 and related viral diseases.

scholarly journals Label Free Detection of Adenosine Based on Hemin/G-Quadruplex Peroxidase-Mimicking DNAzyme as Bioelectrocatalyst

2013 ◽  
Vol 25 (18) ◽  
pp. 10541-10545 ◽  
Author(s):  
Yu Li ◽  
Sen Li ◽  
Ge-Qing Xia ◽  
Yuansheng Wang
Keyword(s):  
Label Free ◽  
Label Free Detection ◽  
G Quadruplex

Cationic-perylene-G-quadruplex complex based fluorescent biosensor for label-free detection of Pb 2+

Talanta ◽  
2016 ◽  
Vol 149 ◽  
pp. 98-102 ◽  
Author(s):  
Xu-Hua Zhao ◽  
Liang Gong ◽  
Yuan Wu ◽  
Xiao-Bing Zhang ◽  
Jun Xie
Keyword(s):  
Label Free ◽  
Fluorescent Biosensor ◽  
Label Free Detection ◽  
G Quadruplex
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