Uniformly distributed and in situ iron–nitrogen co-doped porous carbon derived from pork liver for rapid and simultaneous detection of dopamine, uric acid, and paracetamol in human blood serum

Abstract

As a biomass-derived precursor, pork liver, with rich nitrogen, iron, and carbon, was calcined, metal organic ligands were carbonized, and a uniformly distributed and in situ iron–nitrogen co-doped porous carbon material (N/Fe–C) could be prepared by a facile, low-cost synthetic method. Using N/Fe–C as an electrochemical selective sensor, a biochemical analysis platform was proposed. The neurotransmitter dopamine (DA), the purine metabolite uric acid (UA), and the most extensively employed drug paracetamol (PA) could coexist in real biological samples and used as models of bioelectroactive molecules. Compared with glassy carbon electrode (GCE), GCE modified with nitrogen-doped carbon (C/N/GCE) and N–C/GCE (i.e., the iron in N/Fe–C/GCE removed with nitric acid), the redox performance of N/Fe–C/GCE was improved approximately 18-fold, 6-fold, and 2-fold, respectively. Furthermore, the peak overlap among DA, UA, and PA and the interference of ascorbic acid, H₂O₂ and glucose could be avoided. These improvements were attributed to the uniform distribution of N, C and Fe, electrocatalytic activity of iron, excellent electrical conductivity of graphite-like carbon, large surface area (665.1 m² g⁻¹), and outstanding, but different, redox ability for DA, UA, and PA. N/Fe–C/GCE was utilized for rapid (in 30 s) and simultaneous determination of DA, UA, and PA. The linear range and detection limit (3 S/N) were in the range of 0.5–320 μmol L⁻¹ and 10.6–79.0 nmol L⁻¹, respectively. This method was used for the analysis of human blood serum with satisfactory results. The electrode of N/Fe–C/GCE remained effective for at least two weeks.