Electro‐oxidized Monolayer CVD Graphene Film Transducer for Ultrasensitive Impedimetric DNA Biosensor

Abstract

We report the effect of electrochemical anodization on the properties of monolayer graphene as the main aim of this research and consequently using the resulting label‐free impedimetric biosensor for DNA sequences detection. Monolayer graphene was grown by chemical vapor deposition (CVD) with methane as precursor on copper foil, transferred onto a glassy carbon electrode and electrochemically anodized. Raman spectroscopy and X‐Ray photo electron spectroscopy revealed enhancement of defect density, roughness and formation of C−O−C, C−O−H and C=O functional groups after anodization. Amine‐terminated poly T probe was linked covalently to the carboxylic groups of anodized graphene by the zero‐length linker to fabricate the impedance‐based DNA biosensor. The anodized graphene electrode demonstrated a superior performance for electrochemical impedance detection of DNA. The DNA biosensor showed a large linear dynamic range from 2.0×10−18 to 1.0×10−12 M with a limit of detection of 1.0×10−18 M using electrochemical impedance spectroscopy (EIS) method. Equivalent circuit modeling shows that DNA hybridization is detected through a change in charge transfer resistance.

Reduced Graphene Oxide/TEMPO-Nanocellulose Nanohybrid-Based Electrochemical Biosensor for the Determination ofMycobacterium tuberculosis

“…Reduced graphene oxide (rGO) or synonyms as functionalized graphene oxide [32] provides abundant structural defects and accessible functional groups which advantages as an immobilization matrix for biological element recognition. Hence, it is expected that rGO-based hybrid materials can further improve the performance of electrochemical biosensors [33].…”

Employing Label‐free Electrochemical Biosensor Based on 3D‐Reduced Graphene Oxide and Polyaniline Nanofibers for Ultrasensitive Detection of Breast Cancer BRCA1 Biomarker

“…In order to improve the cure rate, the ultrasensitive DNA biosensors are making remarkable progress for early-stage cancer detection [11][12][13]. The label-based techniques such as in-situ hybridization, reverse transcription polymerase chain reaction, microarrays, and surface plasmon resonance [14], require expensive fluorescent dyes or commercial kits, show limited sensitivity and selectivity, as well as time-consuming [15][16][17]. Recently, more and more researchers have paid attention to label-free procedures of DNA sensors, because of their minimal sample preparation requirements, as well as easiness, rapidness and cost-effective [18][19][20][21].…”

Highly Sensitive Electrochemical Biosensor Using Folic Acid-Modified Reduced Graphene Oxide for the Detection of Cancer Biomarker

“…Graphene-based materials are widely employed in drug/gene delivery, biosensing, and photothermal therapy applications [49,50]. In addition to excellent conductivity, graphene-based materials have advantages such as easy functionalization, biocompatible nature, and good stability in physiological conditions, making it a versatile transducer material [51][52][53][54][55][56][57]. Moreover, due to the high surface area and rich π conjugation structure, graphene-based structures offer an excellent platform for the effective loading of bio-recognition elements [58].…”