Graphene and carbon quantum dots electrochemistry

Lim, Chu Sing; Holá, Kateřina; Ambrosi, Adriano; Zbořil, Radek; Pumera, Martin

doi:10.1016/j.elecom.2015.01.023

Cited by 105 publications

(62 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…CDs also possess special mellifluous traits such as photoluminescence, low toxicity, water solubility, high chemical stability, easy functionalization, and impressive biocompatibility . These properties have been used extensively in various fields such as electrochemistry, wastewater treatment, photocatalysis, bio‐imaging, light emitting devices, sensing, etc.…”

Section: Introductionmentioning

confidence: 99%

A facile synthesis of nontoxic luminescent carbon dots for detection of chromium and iron in real water sample and bio‐imaging

et al. 2019

View full text Add to dashboard Cite

In this study, we have reported the synthesis of luminescent carbon dots (CDs) from indigenous potato sources by simple heating reactions. The as‐synthesized CDs exhibited an average size of ~ 5.97 nm with a quantum yield (QY) of 6.08%. Furthermore, the CDs possessed high water‐solubility, possibly due to the presence of ─COOH and ─OH groups on their surfaces. The quenching of luminescence of the CDs specifically by Cr6+ and Fe3+ ions was used to detect chromium and iron in the water sample. The minimum limit of detection (LOD) for Cr6+ and Fe3+ ions was found to be 0.012 μM and 0.000549 μM, respectively, in a linear range of 0.5 μM‐100 μM and 0.5 μM‐5 μM for Cr6+ and Fe3+, respectively, which was well below the concentration specified by WHO. We used our sensing system to detect the metal ions in water from the Brahmaputra River as well as in tannery water. In addition, the MTT‐based cell viability experiments showed that the CDs were nontoxic within 200 μg/mL. High quantum yield and the easy uptake of CDs enabled the quick labelling of cytoplasm of the HeLa cells, which can be further attributed to bioimaging applications.

show abstract

Section: Introductionmentioning

confidence: 99%

A facile synthesis of nontoxic luminescent carbon dots for detection of chromium and iron in real water sample and bio‐imaging

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Raman spectra of the CNDs (Figure 1E) show both the D bands at 1341 cm −1 (sp 3 -hybridized) and G bands at 1564 cm −1 (sp 2 -hybridized) with an intensity ratio I D /I G of about 1.06, suggesting the presence of a disordered graphite structure. 32, 33 The main diffraction peak in the XRD spectrum (Figure 1F) appears at 25.2° with a full width at half maximum (FWHM) of about 3.2°,which corresponds to an interlayer distance of 0.35 nm between the planar carbon based sheets for graphite structure region. 34 The zeta potential of the CNDs was −22.3 mV at a pH of 5.86 (Table S4), owing to the presence of carboxylate groups on the surface; further corroborating that the CNDs are highly dispersed and stable in the aqueous system.…”

Section: Resultsmentioning

confidence: 99%

A fluorescence-electrochemical study of carbon nanodots (CNDs) in bio- and photoelectronic applications and energy gap investigation

Zeng

Zhang

Arvapalli

et al. 2017

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

Carbon nanodots (CNDs) have attracted great attention due to their superior solubility, biocompatibility, tunable photoluminescence, and opto-electronic properties. This work describes a new fluorescence-based spectroelectrochemistry approach to simultaneously study the photoluminescence and wavelength dependent photocurrent of microwave synthesized CNDs. The fluorescence of CNDs has a selective quench upon a reversible redox couple, ferricyanide/ferrocyanide,− reaction during the cyclic voltammetry. The CNDs modified gold slide electrode demonstrates wavelength dependent photocurrent generation during the fluorescence-electrochemical study, suggesting potential application in photoelectronics. UV-Vis absorption and electrochemistry are used to quantify the energy gap of the CNDs, and then to calibrate a Hückel model for the CNDs electronic energy levels. The Hückel (or tight binding) model treatment of an individual CND as a molecule combines the conjugated π states (C=C) with the functional groups (C=O, C-O, and COOH) associated with the surface electronic states. This experimental and theoretical investigation of the CNDs provides a new perspective on the optoelectronic properties of CNDs and should aid in their development for practical use in biomedicine, chemical sensing, and photoelectric devices.

show abstract

“…Based on the results obtained from cyclic voltammetry studies, CQDs somehow impart improved electron transfer characteristics using ferro/ferricyanide as redox couple (Figure 8A). 76 The importance of surface functionalities on the electrochemical response has been demonstrated by Marken and co-workers in several papers. [77][78][79] The hydrothermal conversion of chitosan leads to electrochemically inactive carbon nanomaterials, while "hydrothermal wrapping" of a negatively charge Pd-carbon core shell particles with chitosan gave a positively charged nanocomposite ( Figure 8B).…”

Section: Redox Properties Of Carbon-based Quantum Particlesmentioning

confidence: 99%