Graphene Defects in Saccharide Carbon Dots Govern Electrochemical Sensitivity

Abstract

Galactose (Gal), lactose (Lac), and glucose (Glu) derived carbon dots (CDs) were evaluated for their utility as electrochemical sensing composites using acetaminophen (APAP) as a probe molecule. The goal of this work is to ascertain the role of graphene defects on electrochemical activity. Higher sp2‐to‐sp3 hybridized carbon ratios (in parentheses) in the CDs correlated with higher sensitivity in the order according to measured Raman IG/ID intensities: GluCDs (6.53)<LacCDs (9.30)<GalCDs (10.18). A dynamic measurement in the 0–2.0 mmol dm−3 APAP range at pH=7.0 was achieved, suitable for practical APAP toxicity monitoring. Defect density within the GalCDs provided the highest sensitivity.

Role of defects and exposed graphene in carbon nanomaterial-based electrocatalysts

“…To explore whether the effects of current are universally proportional to graphene sheet exposure, we carried out experiments on an array of saccharide-based carbon dots, where the I D / I G ratio was varied based on the ‘sweet taste’ characteristic (which summarizes molar volume, solute/solute interactions, and intramolecular H-bonding) of the saccharide precursors. 31 Acetaminophen (APAP) was used as the probe molecule for redox detection using galactose CDs (GalCDs), lactose CDs (LacCDs), and glucose CDs (GluCDs) (Fig. 10A).…”