A novel label-free biosensor based on self-assembled aptamer/GO architecture for sensitive detection of biomolecules

2015 ◽  
Vol 7 (13) ◽  
pp. 5606-5610 ◽  
Author(s):  
Zhimei Huang ◽  
Jia Ge ◽  
Lan Liu ◽  
Jianhui Jiang ◽  
Guoli Shen ◽  
...  
Keyword(s):  
Conformational Change ◽  
Thioflavin T ◽  
Sensitive Detection ◽  
Label Free ◽  
Biomolecule Detection ◽  
Self Assembled ◽  
Detection Of Biomolecules

We developed a novel label-free biosensor for biomolecule detection based on the thioflavin T (ThT)-induced conformational change of guanine-rich oligonucleotides and self-assembled aptamer/GO nanosheet architecture.

Improved Sensitivity of Dielectric Modulated Junctionless Transistor for Nanoscale Biosensor Design

2020 ◽  
Vol 18 (4) ◽  
pp. 328-333
Author(s):  
Shradhya Singh ◽  
Shashi Bala ◽  
Balwant Raj ◽  
Balwinder Raj
Keyword(s):  
Threshold Voltage ◽  
Drain Current ◽  
Label Free ◽  
Asymmetric Mode ◽  
Biomolecule Detection ◽  
Gate Operation ◽  
Voltage Change ◽  
Mode Of Operation ◽  
Junctionless Transistor ◽  
Detection Of Biomolecules

This work has proposed a device i.e., Dielectric Modulated (DM) Junctionless Transistor which is utilizes as Label-Free (LF) electrical characteristic detection of bio-molecules. The electrical characteristics used for the detection of biomolecules are electric field, surface potential, drain current and threshold voltage (Vth). Due to immobilization of biomolecules in the cavity region, the threshold voltage change in comparison to the absence of biomolecule, which is utilizes as the sensitivity metric. The sensitivity of biomolecule detection can be enhanced by using asymmetric gate operation of the device. In asymmetric mode the degree of sensitivity is almost five times higher than that of the symmetric mode of operation.

Fluorescence assay based on the thioflavin T-induced conformation switch of G-quadruplexes for TET1 detection

The Analyst ◽  
2021 ◽  
Vol 146 (7) ◽  
pp. 2126-2130
Author(s):  
Xue Chen ◽  
Ying Cheng ◽  
Yafen Wang ◽  
Jing Tang ◽  
Fang Wang ◽  
...  
Keyword(s):  
Fluorescence Assay ◽  
Fluorescence Method ◽  
Thioflavin T ◽  
Sensitive Detection ◽  
Label Free ◽  
Specific Design ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

A simple and label-free fluorescence method is developed for the highly sensitive detection of TET1 based on ThT/G-quadruplexes in combination with the specific design of oligonucleotides.

A microfluidic device with integrated impedance detection for λ-DNA

2003 ◽  
Vol 773 ◽  
Author(s):  
Myung-Il Park ◽  
Jonging Hong ◽  
Dae Sung Yoon ◽  
Chong-Ook Park ◽  
Geunbae Im
Keyword(s):  
Microfluidic Device ◽  
Electrochemical Impedance ◽  
Direct Detection ◽  
Full Potential ◽  
Label Free ◽  
Buffer Solution ◽  
Detection Systems ◽  
Significant Difference ◽  
Detection Of Biomolecules ◽  
Impedance Magnitude

AbstractThe large optical detection systems that are typically utilized at present may not be able to reach their full potential as portable analysis tools. Accurate, early, and fast diagnosis for many diseases requires the direct detection of biomolecules such as DNA, proteins, and cells. In this research, a glass microchip with integrated microelectrodes has been fabricated, and the performance of electrochemical impedance detection was investigated for the biomolecules. We have used label-free λ-DNA as a sample biomolecule. By changing the distance between microelectrodes, the significant difference between DW and the TE buffer solution is obtained from the impedance-frequency measurements. In addition, the comparison for the impedance magnitude of DW, the TE buffer, and λ-DNA at the same distance was analyzed.

scholarly journals Microfluidic Impedance Biosensor Chips Using Sensing Layers Based on DNA-Based Self-Assembled Monolayers for Label-Free Detection of Proteins

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 80
Author(s):  
Khaled Alsabbagh ◽  
Tim Hornung ◽  
Achim Voigt ◽  
Sahba Sadir ◽  
Taleieh Rajabi ◽  
...  
Keyword(s):  
Troponin I ◽  
Electrochemical Impedance ◽  
Specific Binding ◽  
Self Assembled Monolayers ◽  
Significant Shift ◽  
Label Free ◽  
Label Free Detection ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Biosensor Chip

A microfluidic chip for electrochemical impedance spectroscopy (EIS) is presented as bio-sensor for label-free detection of proteins by using the example of cardiac troponin I. Troponin I is one of the most specific diagnostic serum biomarkers for myocardial infarction. The microfluidic impedance biosensor chip presented here consists of a microscope glass slide serving as base plate, sputtered electrodes, and a polydimethylsiloxane (PDMS) microchannel. Electrode functionalization protocols were developed considering a possible charge transfer through the sensing layer, in addition to analyte-specific binding by corresponding antibodies and reduction of nonspecific protein adsorption to prevent false-positive signals. Reagents tested for self-assembled monolayers (SAMs) on gold electrodes included thiolated hydrocarbons and thiolated oligonucleotides, where SAMs based on the latter showed a better performance. The corresponding antibody was covalently coupled on the SAM using carbodiimide chemistry. Sampling and measurement took only a few minutes. Application of a human serum albumin (HSA) sample, 1000 ng/mL, led to negligible impedance changes, while application of a troponin I sample, 1 ng/mL, led to a significant shift in the Nyquist plot. The results are promising regarding specific detection of clinically relevant concentrations of biomarkers, such as cardiac markers, with the newly developed microfluidic impedance biosensor chip.

scholarly journals Development of a Novel Label-Free and High-Throughput Arginase-1 Assay Using Self-Assembled Monolayer Desorption Ionization Mass Spectrometry

2021 ◽  
pp. 247255522110006
Author(s):  
Michael D. Scholle ◽  
Zachary A. Gurard-Levin
Keyword(s):  
Mass Spectrometry ◽  
Drug Discovery ◽  
High Throughput ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Label Free ◽  
Desorption Ionization ◽  
Arginase 1 ◽  
Self Assembled ◽  
High Throughput Assay

Arginase-1, an enzyme that catalyzes the reaction of L-arginine to L-ornithine, is implicated in the tumor immune response and represents an interesting therapeutic target in immuno-oncology. Initiating arginase drug discovery efforts remains a challenge due to a lack of suitable high-throughput assay methodologies. This report describes the combination of self-assembled monolayers and matrix-assisted laser desorption ionization mass spectrometry to enable the first label-free and high-throughput assay for arginase activity. The assay was optimized for kinetically balanced conditions and miniaturized, while achieving a robust assay (Z-factor > 0.8) and a significant assay window [signal-to-background ratio > 20] relative to fluorescent approaches. To validate the assay, the inhibition of the reference compound nor-NOHA (Nω-hydroxy-nor-L-arginine) was evaluated, and the IC50 measured to be in line with reported results (IC50 = 180 nM). The assay was then used to complete a screen of 175,000 compounds, demonstrating the high-throughput capacity of the approach. The label-free format also eliminates opportunities for false-positive results due to interference from library compounds and optical readouts. The assay methodology described here enables new opportunities for drug discovery for arginase and, due to the assay flexibility, can be more broadly applicable for measuring other amino acid–metabolizing enzymes.

A label-free electrochemical aptasensor based on the core–shell Cu-MOF@TpBD hybrid nanoarchitecture for the sensitive detection of PDGF-BB

The Analyst ◽  
2021 ◽  
Author(s):  
Ya Li ◽  
Zhiling Liu ◽  
Wenbo Lu ◽  
Man Zhao ◽  
He Xiao ◽  
...  
Keyword(s):  
Hybrid Nanocomposites ◽  
Sensitive Detection ◽  
Core Shell ◽  
Label Free ◽  
Electrochemical Aptasensor ◽  
The Core

A novel label-free electrochemical aptasensor based on core–shell Cu-MOF@TpBD hybrid nanocomposites has been prepared for the sensitive detection of PDGF-BB.

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