Fluorescence and Sensing Applications of Graphene Oxide and Graphene Quantum Dots: A Review

Abstract

Graphene oxide and graphene quantum dots are attractive fluorophores, which are inexpensive, non-toxic, photo-stable, water-soluble, biocompatible and environmentally friendly. They find extensive applications in fluorescent biosensors and chemi-sensors, in which they either serve as fluorophores or quenchers. As fluorophores, they display the tunable photoluminescence emission and the “Giant Red-Edge Effect”. As quenchers, they exhibit a remarkable quenching efficiency via either electron transfer or Förster resonance energy transfer (FRET) process. In this review article, the origin of fluorescence and the mechanism of excitation wavelength-dependent fluorescence of graphene oxide and graphene quantum dots are discussed. The sensor design strategies based on graphene oxide and graphene quantum dots are presented. The applications of such sensors in health care, environment, agriculture and food safety are highlighted.

Spectroelectrochemistry of Quantum Dots

“…The UV/VIS absorption spectrum of graphene QDs (GQDs) shows two main peaks, one around 230 nm assigned to π-π* transition of C sp 2 bonds and a shoulder at about 300 nm related to n-π* transitions of C=O or CÀ O bonds. [1,[35][36][37] As in the case of QDs, GQDs show PL at very different wavelengths depending on its size, from deep ultraviolet to red. [36] The PL mechanism is related to the quantum confinement effect, emissive traps, excitons of carbon, aromatic structures, oxygen-containing groups, free zigzag sites and edge defects.…”

“…PL depends not only on size, but also on the excitation wavelength, oxidation degree, solvent, pH, functionalization, etc. [1,[35][36][37] A number of potential applications have been proposed for GQDs. [8,38] The most attractive characteristic of GQDs with respect to semiconductor QDs is the high availability of carbon.…”

Nano‐Graphene Oxide Based Multichannel Sensor Arrays towards Sensing of Protein Mixtures

“…After its discovery, graphene oxide (GO) has been supporting as a platform for diverse applications like biosensing, molecular recognition, catalysis and biomedical applications etc. In compare to the conventional polydisperse GO, monodisperse nGO plays a very crucial role in array‐based sensing at point of sensitivity and consistency .…”

Fellows of the Electrochemical Society: C. Amatore, K. Amine, P. Atanassov, C. P. Grey, Y. Shao‐Horn, and N. Wu / Priestley Medal: G. Richmond / Förderungspreis der Stadt Wien: N. Maulide

“…Anschließend war er Postdoc bei Jean-Paul Issi an der UniversitØ catholique de Louvain (1990) und Tsuyoshi Nakajima an der UniversitätK yōto (1992)(1993)(1994) (1998)(1999) und der University of Pittsburgh (1999Pittsburgh ( -2001 [6] Angewandte Chemie Nachrichten Vorgestellt … Anschließend war er Postdoc bei Jean-Paul Issi an der UniversitØ catholique de Louvain (1990) und Tsuyoshi Nakajima an der UniversitätK yōto (1992)(1993)(1994) (1998)(1999) und der University of Pittsburgh (1999Pittsburgh ( -2001 [6] Angewandte Chemie Nachrichten Vorgestellt ……”

“…Khalil Amine (Argonne National Laboratory) studierte an der UniversitØ de Bordeaux und promovierte dort 1989 bei Alain Tressaud. Anschließend war er Postdoc bei Jean-Paul Issi an der UniversitØ catholique de Louvain (1990) und Tsuyoshi Nakajima an der UniversitätK yōto (1992)(1993)(1994) [6] Angewandte Chemie Nachrichten Vorgestellt ……”