Facile preparation of metal-free graphitic-like carbon nitride/graphene oxide composite for simultaneous determination of uric acid and dopamine

• Published in: Microchemical journal 2023-07, Vol.190, p.108726, Article 108726
• Main Authors: Xia, Yonghui, Li, Guangli, Zhu, Yuefang, He, Quanguo, Hu, Changping
• Format: Article
• Language: English
• Subjects: Dopamine; Graphene oxide; Graphitic-like carbon nitride; Human serum; Uric acid
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2023.108726

[Display omitted] •g-C3N4/GO was designed as a metal-free electrocatalyst for uric acid and dopamine.•g-C3N4/GO showed good electrocatalytic performance for the oxidation of uric acid and dopamine.•The sensor achieved the simultaneous determination of uric acid and dopamine at nanomolar level.•The sensor showed satisfactory reproducibility, selectivity and stability. Graphitic-like carbon nitride/graphene oxide composite nanosheets (g-C3N4/GO) were synthesized for simultaneous determination of uric acid (UA) and dopamine (DA). The surface features and electrochemical properties of the g-C3N4/GO were investigated by scanning electron microscopy, X-ray diffraction, cyclic voltammetry and electrochemical impedance spectra. The voltammetric responses of UA and DA were determinated by cyclic voltammetry and differential pulse voltammetry. g-C3N4/GO had significantly improved electrical conductivity, selective oxidation capacity and electrocatalytic activity. The proposed g-C3N4/GO modified glassy carbon electrode (GCE) consequently displayed excellent electrocatalytic activity for UA and DA, with a broad linear detection range (0.03–30 μM) and extremely low detection limits (UA 4.6 nM; DA 5.4 nM). The proposed g-C3N4/GO/GCE also demonstrated excellent reproducibility, selectivity and stability. The levels of UA and DA in human serum were measured by the g-C3N4/GO/GCE, and then the known concentrations of UA and DA were spiked to the samples, which proved that the recoveries were good.