Doping effects of surface functionalization on graphene with aromatic molecule and organic solvents

Wu, Guangfu; Tang, Xin; Meyyappan, M.; Lai, King Wai Chiu

doi:10.1016/j.apsusc.2017.07.048

Cited by 87 publications

(68 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The decrease in I 2D /I G and the upshift in 2D peak that were observed after both modifications indicate the p-doping effect on graphene. These observations of 2D peak shift are in agreement with previous experimental results on PBSE-modified [32] and nitrophenyl-modified graphene [13]. Thus, these Raman spectra confirmed that the noncovalently and covalently modified graphene electrodes were prepared.…”

Section: Characterization Of Modified Graphene Electrodessupporting

confidence: 92%

“…For the noncovalent modified graphene, the 2D (2688 cm −1 ) peak shows slight upshift compared to the unmodified graphene, while the G peak (1590 cm −1 ) is shown at similar wavenumber. In addition, the appearance of a D' peak (1622 cm −1 ) was observed, which is mainly caused by defects generated via an intravallery double-resonance process [31], and it was also observed in the Raman spectra of other PBSE-modified graphene [32]. Thus, the change of the Raman spectrum suggests the attachment of the pyrenyl groups onto the graphene surface.…”

Section: Characterization Of Modified Graphene Electrodesmentioning

confidence: 83%

See 1 more Smart Citation

Electrochemical Characterization of CVD-Grown Graphene for Designing Electrode/Biomolecule Interfaces

2020

View full text Add to dashboard Cite

In research on enzyme-based biofuel cells, covalent or noncovalent molecular modifications of carbon-based electrode materials are generally used as a method for immobilizing enzymes and/or mediators. However, the influence of these molecular modifications on the electrochemical properties of electrode materials has not been clarified. In this study, we present the electrochemical properties of chemical vapor deposition (CVD)-grown monolayer graphene electrodes before and after molecular modification. The electrochemical properties of graphene electrodes were evaluated by cyclic voltammetry and electrochemical impedance measurements. A covalently modified graphene electrode showed an approximately 25-fold higher charge transfer resistance than before modification. In comparison, the electrochemical properties of a noncovalently modified graphene electrode were not degraded by the modification.

show abstract

Section: Characterization Of Modified Graphene Electrodessupporting

confidence: 92%

Section: Characterization Of Modified Graphene Electrodesmentioning

confidence: 83%

Electrochemical Characterization of CVD-Grown Graphene for Designing Electrode/Biomolecule Interfaces

2020

View full text Add to dashboard Cite

show abstract

“…After PBASE was applied to the graphene surface, the statistical data of the 2D peak position were shifted to a higher frequency (∼3.27 cm −1 ), indicating p-doping by the π−π interaction between PBASE and graphene ( Figure 2C). 23,24 The mapping images also show that the average I 2D /I G ratio of PBASE-treated graphene (I 2D /I G = ∼1.87) is significantly lower than that of pristine graphene (I 2D /I G = ∼3.61) due to existence of some disorder on the graphene ( Figure 2D,E). The XPS survey data show the principal C 1s, O 1s, and N 1s core levels ( Figure 2F).…”

Section: Acs Nano Wwwacsnanoorg Articlementioning

confidence: 93%

Rapid Detection of COVID-19 Causative Virus (SARS-CoV-2) in Human Nasopharyngeal Swab Specimens Using Field-Effect Transistor-Based Biosensor

et al. 2020

View full text Add to dashboard Cite

Coronavirus disease 2019 (COVID-19) is a newly emerging human infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, previously called 2019-nCoV). Based on the rapid increase in the rate of human infection, the World Health Organization (WHO) has classified the COVID-19 outbreak as a pandemic. Because no specific drugs or vaccines for COVID-19 are yet available, early diagnosis and management are crucial for containing the outbreak. Here, we report a field-effect transistor (FET)-based biosensing device for detecting SARS-CoV-2 in clinical samples. The sensor was produced by coating graphene sheets of the FET with a specific antibody against SARS-CoV-2 spike protein.The performance of the sensor was determined using antigen protein, cultured virus, and nasopharyngeal swab specimens from COVID-19 patients. Our FET device could detect the SARS-CoV-2 spike protein at concentrations of 1 fg/mL in phosphate-buffered saline and 100 fg/mL clinical transport medium. In addition, the FET sensor successfully detected SARS-CoV-2 in culture medium (limit of detection [LOD]: 1.6 × 10 1 pfu/mL) and clinical samples (LOD: 2.42 × 10 2 copies/mL). Thus, we have successfully fabricated a promising FET biosensor for SARS-CoV-2; our device is a highly sensitive immunological diagnostic method for COVID-19 that requires no sample pretreatment or labeling.

show abstract

“…Usually, surface functionalization is considered to control device's signal. One recent study has indicated the correlation between aromatic molecule and buffer solution during functionalization . Graphene has excellent properties such as high carrier mobility, outstanding electronic conductivity, and large specific area that make it a promising sensing material for the development of biosensors .…”

Section: Introductionmentioning

confidence: 99%

Graphene Field‐Effect Transistors for the Sensitive and Selective Detection of Escherichia coli Using Pyrene‐Tagged DNA Aptamer

Dai

Tang

et al. 2017

Adv Healthcare Materials

Self Cite

View full text Add to dashboard Cite

This study reports biosensing using graphene field-effect transistors with the aid of pyrene-tagged DNA aptamers, which exhibit excellent selectivity, affinity, and stability for Escherichia coli (E. coli) detection. The aptamer is employed as the sensing probe due to its advantages such as high stability and high affinity toward small molecules and even whole cells. The change of the carrier density in the probe-modified graphene due to the attachment of E. coli is discussed theoretically for the first time and also verified experimentally. The conformational change of the aptamer due to the binding of E. coli brings the negatively charged E. coli close to the graphene surface, increasing the hole carrier density efficiently in graphene and achieving electrical detection. The binding of negatively charged E. coli induces holes in graphene, which are pumped into the graphene channel from the contact electrodes. The carrier mobility, which correlates the gate voltage to the electrical signal of the APG-FETs, is analyzed and optimized here. The excellent sensing performance such as low detection limit, high sensitivity, outstanding selectivity and stability of the graphene biosensor for E. coli detection paves the way to develop graphene biosensors for bacterial detection.

show abstract

Doping effects of surface functionalization on graphene with aromatic molecule and organic solvents

Cited by 87 publications

References 44 publications

Electrochemical Characterization of CVD-Grown Graphene for Designing Electrode/Biomolecule Interfaces

Electrochemical Characterization of CVD-Grown Graphene for Designing Electrode/Biomolecule Interfaces

Rapid Detection of COVID-19 Causative Virus (SARS-CoV-2) in Human Nasopharyngeal Swab Specimens Using Field-Effect Transistor-Based Biosensor

Graphene Field‐Effect Transistors for the Sensitive and Selective Detection of Escherichia coli Using Pyrene‐Tagged DNA Aptamer

Contact Info

Product

Resources

About