One-step synthesis of fluorescent graphene quantum dots as an effective fluorescence probe for vanillin detection

Abstract

This study proposes an easy bottom-up method for the synthesis of photoluminescent (PL) graphene quantum dots (GQDs) using citric acid as the carbon source.

GQD@NiFe‐LDH Nanosheets for Photocatalytic Activity towards Textile Dye Degradation via Lattice Contraction

“…−OH, etc.) attached to it, which is well matched with HRTEM results with increasing d‐spacing of GQDs [52,54] . The inset of Figure 3b represents the color of GQDs aqueous solution is pale yellow under visible light in contrast to the blue fluorescence when excited at 365 nm that confirms the particle size of GQDs is very small and the band gap opens up in a size‐dependent manner according to quantum confinement effect and edge effect.…”

“…Preparation of GQDs : GQDs were synthesized by the pyrolysis of citric acid [52] . Initially, 2 g of citric acid was placed in a silica crucible and heated in an air oven at 180 °C for 15 min.…”

“…Preparation of GQDs: GQDs were synthesized by the pyrolysis of citric acid. [52] Initially, 2 g of citric acid was placed in a silica crucible and heated in an air oven at 180 °C for 15 min. The color of citric acid changes from yellow to light orange by increasing the temperature to 200 °C for another 15 min.…”

Zero-Dimensional Carbon Nanomaterials for Fluorescent Sensing and Imaging

“…Organic precursors can facilitate the formation of 0D CNMs exhibiting uniform sizes and morphologies and conveniently regulated functional groups . Small molecules, such as citric acid, glucose, urea, thiourea, thiols, and amino acids, which possess several carboxyl and amino groups, are mostly used organic ingredients. − Once the sp 2 -conjugated domain is extended in precursors, the fluorescence emission of prepared 0D CNMs can be extended to the longer wavelength region, which is highly suitable for constructing red- or near-infrared-emission products . Therefore, aromatic derivatives, such as phenols and aromatic amines, are mostly employed because they can not only produce a large π-conjugated system but also provide active electron donor groups and hydrogen atoms to extend the n –π conjugation and improve the water solubility .…”

Tetrahedrally Structured CaMoO4 Nanospheres on Heteroatom-Doped Carbon Nanotubes for Sensitive Food Additive Electrochemical Sensors

“…To enhance food safety and addiction prevention, particularly in young children, it is necessary to achieve a rapid and quantitative determination method for Vanillin. People are increasingly reliant on electrochemical sensors, especially for food analysis. − This target molecule can be detected in a variety of ways, but many methods are time-consuming and expensive, such as high-performance liquid chromatography, capillary electrophoresis, spectrophotometry, fluorescence, and calorimetry. − Despite their accuracy, these analytical methods have high operating costs, time-consuming sample pretreatment processes, and the requirement of skilled personnel. , Alternatively, the electrochemical sensor makes an excellent replacement for Vanillin analysis since Vanillin is an electroactive compound, which can be detected through the oxidation of its molecule. In addition, overpotential conditions and electrode fouling may negatively impact the efficiency of direct determination and the sensitivity of target molecules.…”