Aptamer-functionalized graphene-gold nanocomposites for label-free detection of dielectrophoretic-enriched neuropeptide Y

2016 ◽  
Vol 72 ◽  
pp. 144-147 ◽  
Author(s):  
Renny E. Fernandez ◽  
Bankim J. Sanghavi ◽  
Vahid Farmehini ◽  
Jorge L. Chávez ◽  
Joshua Hagen ◽  
...  
Keyword(s):  
Neuropeptide Y ◽  
Functionalized Graphene ◽  
Label Free ◽  
Label Free Detection ◽  
Gold Nanocomposites

scholarly journals New Ultrasensitive Sandwich-Type Immunoassay of Dendritic Tri-Fan Blade-like PdAuCu Nanoparticles/Amine-Functionalized Graphene Oxide for Label-Free Detection of Carcinoembryonic Antigen

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1256
Author(s):  
Pingping Xu ◽  
Wenpo Feng ◽  
Mei Wang ◽  
Ling Zhang ◽  
Gaofeng Liang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Carcinoembryonic Antigen ◽  
Au Nanoparticle ◽  
Functionalized Graphene ◽  
Label Free ◽  
Functionalized Graphene Oxide ◽  
Amine Functionalized ◽  
Label Free Detection ◽  
Sandwich Type ◽  
Fan Blade

The early detection of tumor markers has an effective role in the treatment of cancer. Here, a new sandwich-type electrochemical immunosensor for early label-free detection of the cancer biomarker carcinoembryonic antigen (CEA) was developed. Dendritic tri-fan blade-like PdAuCu nanoparticles (PdAuCu NPs)/amine functionalized graphene oxide (NH2-GO) were the label of secondary antibodies (Ab2), and Au nanoparticle-decorated polydopamines (Au/PDA) were immobilized on a screen-printed carbon electrode (SPCE) as the substrate materials. Dendritic tri-fan blade-like PdAuCu NPs/NH2-GO was synthesized according to a simple hydrothermal procedure and used to immobilize antibodies (Ab2) with large surfaces areas, increased catalytic properties and good adsorption to amplify the current signals. Subsequently, Ab2/PdAuCu NPs/NH2-GO catalyzed the reduction of H2O2 in the sandwich-type immunoreactions. Under optimal conditions, the immunosensor exhibited a satisfactory response to CEA with a limit detection of 0.07 pg mL−1 and a linear detection range from 0.1 pg mL−1 to 200 ng mL−1. The proposed immunosensor could be suitable enough for a real sample analysis of CEA, and has clinical value in the early diagnosis of cancer.

scholarly journals Measurement of cytokine biomarkers using an aptamer-based affinity graphene nanosensor on a flexible substrate toward wearable applications

Nanoscale ◽  
2018 ◽  
Vol 10 (46) ◽  
pp. 21681-21688 ◽  
Author(s):  
Zhuang Hao ◽  
Ziran Wang ◽  
Yijun Li ◽  
Yibo Zhu ◽  
Xuejun Wang ◽  
...  
Keyword(s):  
Field Effect ◽  
Field Effect Transistor ◽  
Flexible Substrate ◽  
Functionalized Graphene ◽  
Label Free ◽  
Polyethylene Naphthalate ◽  
Graphene Field Effect Transistor ◽  
Label Free Detection ◽  
Effect Transistor

We present an approach for the label-free detection of cytokine biomarkers using an aptamer-functionalized, graphene field effect transistor (GFET) nanosensor on a flexible, SiO2-coated polymer polyethylene naphthalate (PEN).

scholarly journals The Role of Surface Chemistry in the Efficacy of Protein and DNA Microarrays for Label-Free Detection: An Overview

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1026
Author(s):  
Elisa Chiodi ◽  
Allison M. Marn ◽  
Matthew T. Geib ◽  
M. Selim Ünlü
Keyword(s):  
Surface Chemistry ◽  
Surface Functionalization ◽  
Dna Microarrays ◽  
Label Free ◽  
Polymeric Coatings ◽  
Label Free Detection ◽  
Particle Imaging ◽  
Single Particle Imaging ◽  
The Impact

The importance of microarrays in diagnostics and medicine has drastically increased in the last few years. Nevertheless, the efficiency of a microarray-based assay intrinsically depends on the density and functionality of the biorecognition elements immobilized onto each sensor spot. Recently, researchers have put effort into developing new functionalization strategies and technologies which provide efficient immobilization and stability of any sort of molecule. Here, we present an overview of the most widely used methods of surface functionalization of microarray substrates, as well as the most recent advances in the field, and compare their performance in terms of optimal immobilization of the bioreceptor molecules. We focus on label-free microarrays and, in particular, we aim to describe the impact of surface chemistry on two types of microarray-based sensors: microarrays for single particle imaging and for label-free measurements of binding kinetics. Both protein and DNA microarrays are taken into consideration, and the effect of different polymeric coatings on the molecules’ functionalities is critically analyzed.

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.

H2O2-sensitive quantum dots for the label-free detection of glucose

Talanta ◽  
2010 ◽  
Vol 82 (3) ◽  
pp. 997-1002 ◽  
Author(s):  
Mei Hu ◽  
Jing Tian ◽  
Hao-Ting Lu ◽  
Li-Xing Weng ◽  
Lian-Hui Wang
Keyword(s):  
Quantum Dots ◽  
Label Free ◽  
Label Free Detection
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