Novel oxidative cutting graphene oxide to graphene quantum dots for electrochemical sensing application

A label-free electrochemical platform for the highly sensitive detection of hepatitis B virus DNA using graphene quantum dots

“…GQDs was synthesized by a safe and simple bottom-up methods, and can be directly modied onto the surface of glassy carbon electrode (GCE) because of the physical adsorption with van der Waals forces. 18,19 And then we chose K 3 [Fe(CN) 6 ] as the electroactive indicator to detect and monitor what changes were happening on the surface of electrode. 20 The changes caused by DNA immobilization and hybridization were detected by directly monitoring the differential pulse voltammetric (DPV) response.…”

Graphene quantum dots for energy storage and conversion: from fabrication to applications

“…In 2016, Zhang et al prepared GQDs with a grain diameter of 4-10 nm by using an ultrasonic-assisted chemical stripping method and using O 3 and H 2 O 2 to conduct oxidation cutting of GO. 28 Recently, various synthesis methods of GQDs have been reported. However, several limitations such as complicated synthesis procedures, low production yields, expensive equipment, extreme conditions and high cost have hampered their industrial application progress.…”

Shedding Light on Graphene Quantum Dots: Key Synthetic Strategies, Characterization Tools, and Cutting-Edge Applications

“…A top-down approach is based on the disruption of larger graphene-based materials such as graphite, graphene, carbon nanotubes, carbon black, or fullerenes, into small, 0D dots. The tools to assist scientists in breaking these large 1D, 2D, or 3D materials can be either chemical oxidative agents, microwave irradiation, ultrasound, hydrothermal conditions, laser irradiation, electrical currents, or plasma [ 32 , 33 , 34 ]. In the following subsection, both types of methods as well as the properties of produced dots will be discussed in detail, starting with bottom-up strategies ( Section 2.1 ) and later moving on to top-down approaches ( Section 2.2 ), as pictorially summarized in Figure 2 .…”

“…Considering the need for non-toxic methods in GQD synthesis, an O 3 /H 2 O 2 /ultrasound system was prepared for the first time by Wen et al [ 33 ]. A mixture of GO water suspension and 30% aqueous H 2 O 2 was constantly purged with O 3 for 3 h under ultrasonic irradiation at 150 W. The proposed mechanism consists of two steps: (i) C=C and C-C bond oxidation is induced by • OH radicals generated under ultrasound irradiation, where ultrasound increases the • OH amount and encourages molecular vibrations that contribute to GO cutting; (ii) • OH interaction with the GO surface, oxidizing C-O and C=O groups and scissoring GO fragments in GQDs, with -COOH functional groups.…”