Synthesis and application of electrochemically reduced N-rGO-Co(OH)2 nanocomposite for concurrent detection of biomolecules

In present work, we prepared nitrogen doped graphene oxide (N-GO) by using 1,3-xylenediamine (XDA) as nitrogen precursor which was further decorated with Co(OH)2 nanoflower. The physiochemical analysis such as X-ray photoelectron spectroscopy and scanning electron microscopy revealed the successful doping of nitrogen on GO and fine dispersion of Co(OH)2 nanoflower on the surface of N-GO. The as prepared N-GO-Co(OH)2 was electrochemically reduced (N-rGO-Co(OH)2) to precisely adjust its electrochemical properties. The N-rGO-Co(OH)2 was used as a novel electrode modifier for the simultaneous detection of dopamine (DA) and uric acid (UA). From the combined effects of N-doping and excellent electrocatalytic properties of the Co(OH)2 nanoflower, constructed sensor exhibited high electrochemical sensing activity with the wide linear response, limit of detection and limit of quantification of 1.0 × 10−8 M and 3.0 × 10−8 M for DA and 1.0 × 10−7 M and 3.6 × 10−7 M for UA respectively. The N-rGO-Co(OH)2 nanocomposite showed long-term sensing stability, reproducibility and excellent analytical response in urine for DA and UA detection. Furthermore, N-rGO-Co(OH)2 also revealed remarkable anti-interfering behavior towards other biomolecules including ascorbic acid (AA), serotonin (5-HT) and glucose (Glu). The N-rGO-Co(OH)2 nanocomposite manifests intriguing application potential as the candidate for the application of the electrochemical sensor for simultaneous detection of DA and UA.