Graphene Quantum Dots-based Photoluminescent Sensor: A Multifunctional Composite for Pesticide Detection

Abstract

Due to their size and difficulty to obtain, cost/effective biological or synthetic receptors (e.g., antibodies or aptamers, respectively), organic toxic compounds (e.g., less than 1 kDa) are generally challenging to detect using simple platforms such as biosensors. This study reports on the synthesis and characterization of a novel multifunctional composite material, magnetic silica beads/graphene quantum dots/molecularly imprinted polypyrrole (mSGP). mSGP is engineered to specifically and effectively capture and signal small molecules due to the synergy among chemical, magnetic, and optical properties combined with molecular imprinting of tributyltin (291 Da), a hazardous compound, selected as a model analyte. Magnetic and selective properties of the mSGP composite can be exploited to capture and preconcentrate the analyte onto its surface, and its photoluminescent graphene quantum dots, which are quenched upon analyte recognition, are used to interrogate the presence of the contaminant. This multifunctional material enables a rapid, simple and sensitive platform for small molecule detection, even in complex mediums such as seawater, without any sample treatment.

Sensitivity to Heavy-Metal Ions of Unfolded Fullerene Quantum Dots

“…In particular, innovative carbon-based nanomaterials such as graphene quantum dots (GQDs) and graphene oxide quantum dots (GOQDs) have attracted much interest as stable, nontoxic, photoluminescent nanomaterials with possible applications in chemical and biological sensors, drug delivery, bio-imaging and energy conversion [7][8][9][10][11][12][13]. The physical origin of the photoluminescence (PL) from these carbonbased nanoparticles is still quite controversial and different mechanisms have been suggested, possibly acting together, mainly based on quantum confinement in sp 2 domains with a strong influence from edge and oxygen-containing functional groups [14][15][16][17][18].…”

Applications of Graphene Quantum Dots in Biomedical Sensors

“…Such a facile and cost-effective biosensor was developed to interrogate the presence of organophosphate pesticides in food, water and the environment. Another GQD-sensor for the determination of pesticides was constructed by Zor et al As shown in Figure 5B [157]. Herein, a multifunctional nanocomposite, i.e., magnetic silica beads/GQDs/molecularly imprinted polypyrrole (mSGP), was synthesized for specifically capturing and signaling small molecules owing to the synergism offered by this composite in terms of optical, chemical and magnetic features along with molecular imprinting of tributyltin, a genotoxic substance that can cause endocrine disruptions.…”

Carbon-based quantum particles: an electroanalytical and biomedical perspective

“…Magnetic GQDs embedded molecularly imprinted polypyrrole (mSGP) were designed to specifically and effectively capture, pre-concentrate and detect analytes due to the synergy among chemical, magnetic and molecular imprinting properties with the fluorescence properties of GQDs, which are quenched upon analyte recognition. 124 This multifunctional material enables a rapid, simple and sensitive platform for small molecules detection even in complex media such as seawater without any sample treatment.…”