Graphene oxide quantum dots immobilized on mesoporous silica: preparation, characterization and electroanalytical application

Abstract

Graphene oxide quantum dots incorporated into a mesoporous silica network have been used as a modifier of a carbon paste electrode for the determination of antibiotics and hormones.

Rational design of large flat nitrogen-doped graphene oxide quantum dots with green-luminescence suitable for biomedical applications

“…GO samples were prepared according to the previously reported procedure. 67 In brief, 200 mL of a mixture of concentrated H 2 SO 4 and H 3 PO 4 (9 : 1 v/v) was added to graphite powder (1.5 g) in a 500 mL round-bottom flask equipped with a mechanical stir bar. Then KMnO 4 (9 g) was added slowly at room temperature under stirring and after the flask was heated to 50 °C and kept at this temperature for 12 h. The obtained light-pink mixture was cooled down and poured slowly onto ice (400 mL) with 30% H 2 O 2 (20 mL) giving an orange suspension.…”

Short-pulsed Q-switched fiber laser using graphene oxide quantum dots based as saturable absorber

“…2 c shows the Raman spectrum of the GOQDs, where the D (1312 cm-1) and G (1583 cm-1) bands related to graphene oxide [ 30 ] are observed. The intensity of these bands allows us to predict the existence of a restructuring of the carbon atoms in the GOQDs to a sp2 hybridization, associating an increase in the concentration of electrons in the GOQDs [ 31 ]. The change of intensities on D and G bands indicates that the crystal lattice of the GOQDs presents a higher order with fewer defects or impurities compared to the carbonized fibers, as observed in Fig.…”

Cyclodextrin-Modified Nanomaterials for Drug Delivery: Classification and Advances in Controlled Release and Bioavailability

“…Typically, graphene dots have layered structures and a lateral size of up to 100 nm; that is to say, they are small graphene sheets. In contrast, carbon dots have a spherical shape with a diameter of up to 10 nm, which, together with their edge properties and biocompatibility, gives them an advantage in studies on drug transport and release [124].…”