A study on the electro-reductive cycle of amino-functionalized graphene quantum dots immobilized on graphene oxide for amperometric determination of oxalic acid
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Amino-functionalized graphene quantum dots (NH2-GQD) are described for the amperometric determination of oxalic acid. The NH2-GQD were synthesized via a hydrothermal method using hexamethylenetetramine as the source for nitrogen. The average particle size of the GQD is ∼30 nm, which is also supported by TEM. Electrochemical analysis of the NH2-GQD-GO composite on a glassy carbon electrode at pH 7.4 showed a faint reduction peak at −0.6 V vs. SCE, which was enhanced in the presence of oxalic acid. This variation in cathodic current density is an interesting deviation from the usually studied anodic current density for the electrochemical sensors. This is also supported by cyclic voltammetry and time-based amperometric measurements. The electrode has a linear response in the 0.5–2.0 mM and 2.0–55 mM oxalate concentration ranges and a 50 μM detection limit (at S/N = 3). The electrode was successfully applied to the determination of oxalate in spiked urine samples.
KeywordsElectrochemical analysis; cathodic current density Cyclic voltammetry Amperometery
Mr. Praveen Mishra is thankful for the financial and infrastructural support extended by the National Institute of Technology Karnataka, Surathkal, Mangalore.
Compliance with ethical standards
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
- 9.Fan Z, Li Y, Li X, Fan L, Zhou S, Fang D, Yang S (2014) Surrounding media sensitive photoluminescence of boron-doped graphene quantum dots for highly fluorescent dyed crystals, chemical sensing and bioimaging. Carbon 70 (Supplement C:149–156. https://doi.org/10.1016/j.carbon.2013.12.085 CrossRefGoogle Scholar
- 11.Huang H, Liao L, Xu X, Zou M, Liu F, Li N (2013) The electron-transfer based interaction between transition metal ions and photoluminescent graphene quantum dots (GQDs): a platform for metal ion sensing. Talanta 117(Supplement C):152–157. https://doi.org/10.1016/j.talanta.2013.08.055 CrossRefPubMedGoogle Scholar
- 19.Tadi KK, Motghare RV (2013) Potentiometric selective recognition of oxalic acid based on molecularly imprinted polymer. Int J Electrochem Sci 8:3197–3211Google Scholar
- 25.Pfeiffer K, Berg W, Bongartz D, Hesse A (1997) The direct determination of urinary oxalate by non-suppressed ion chromatography. https://doi.org/10.1515/cclm.19188.8.131.525