A magnetically induced self-assembled and label-free electrochemical aptasensor based on magnetic Fe3O4/Fe2O3@Au nanoparticles for VEGF165 protein detection

2021 ◽  
pp. 152362
Author(s):  
Yanling Zhang ◽  
Min Liu ◽  
Shuai Pan ◽  
Lulu Yu ◽  
Shaoshuai Zhang ◽  
...  
Keyword(s):  
Au Nanoparticles ◽  
Protein Detection ◽  
Label Free ◽  
Electrochemical Aptasensor ◽  
Self Assembled ◽  
Magnetic Fe3o4

A label-free electrochemical aptasensor based on leaf-like vanadium disulfide-Au nanoparticles for the sensitive and selective detection of platelet-derived growth factor BB

2015 ◽  
Vol 7 (19) ◽  
pp. 8277-8284 ◽  
Author(s):  
Xue Liu ◽  
Hong-Lei Shuai ◽  
Ke-Jing Huang
Keyword(s):  
Growth Factor ◽  
Hydrothermal Method ◽  
Au Nanoparticles ◽  
Platelet Derived Growth Factor ◽  
Sensitive Detection ◽  
Selective Detection ◽  
Label Free ◽  
Electrochemical Aptasensor ◽  
Facile Hydrothermal Method

In this work, an electrochemical aptasensor for the sensitive detection of platelet-derived growth factor BB (PDGF-BB) is fabricated based on leaf-like VS2 nanosheets which are prepared by a facile hydrothermal method.

scholarly journals Label-Free Electrochemical Aptasensor for Sensitive Detection of Malachite Green Based on Au Nanoparticle/Graphene Quantum Dots/Tungsten Disulfide Nanocomposites

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 229 ◽  
Author(s):  
Qianqian Wang ◽  
Xiaofei Qin ◽  
Liping Geng ◽  
Yan Wang
Keyword(s):  
Quantum Dots ◽  
Malachite Green ◽  
Au Nanoparticles ◽  
Graphene Quantum Dots ◽  
Tungsten Disulfide ◽  
Electrochemical Sensing ◽  
Au Nanoparticle ◽  
Label Free ◽  
Electrochemical Aptasensor ◽  
Fish Samples

A label-free electrochemical aptasensor was fabricated to sensitively determine malachite green (MG) based on Au nanoparticles/graphene quantum dots-tungsten disulfide nanosheet composite film modified glassy carbon electrode (AuNPs/GQDs-WS2/GCE). A facial strategy for the self-assembly of graphene quantum dots (GQDs) on tungsten disulfide nanosheets (WS2) was developed to fabricate 0D/2D nanocomposites. As-prepared GQDs-WS2 hybrids exhibited significantly enhanced electrocatalytic properties, and were first used as electroactive materials to construct electrochemical aptasensor. The AuNPs/GQDs-WS2/GCE was prepared through depositing Au nanoparticles on the surface of the GQDs-WS2 film, which acted as the electrochemical sensing matrix to covalently immobilize the aptamers of MG via the Au–S bond. In this label-free proposal, the aptasensor was applied to detect MG by monitoring voltammetric signal resulted from electrochemical oxidation of the MG captured by the aptamer. Under the optimized conditions, the aptasensor showed a wide linear range from 0.01 to 10 μM for MG detection with a low detection limit of 3.38 nM (S/N = 3). The method was applied to determination of MG in spiked fish samples and gave satisfactory results.

Fabrication of electro-active nano-trans surfaces to design label free electrochemical aptasensor for ochratoxin A detection

2021 ◽  
Vol 379 ◽  
pp. 138172
Author(s):  
Maham Liaqat ◽  
Sara Riaz ◽  
Mian Hasnain Nawaz ◽  
Mihaela Badea ◽  
Akhtar Hayat ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Label Free ◽  
Electrochemical Aptasensor

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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