A novel non-enzymatic sensing platform for determination of 5'-guanosine monophosphate in meat.

Graphitic carbon nitride (g-C3N4) doped carboxylated MWCNTs nanocomposite was synthesized using a simple method. The composite films containing 45 wt%, 50 wt%, 56 wt%, 67 wt% fraction of the carboxylated MWCNTs doped into g-C3N4 were fabricated and characterized. An electrochemical non-enzymatic sensor for determination of 5'-guanosine monophosphate (GMP) based on the nanocomposite was developed. The results indicate that the g-C3N4-carboxylated MWCNTs nanocomposite has highly electrocatalytic activity, good conductivity and biocompatibility, which plays an essential role in the determination of GMP. Under the optimum conditions, the linear fitting equation was I (µA) = -0.0022c (µg·mL-1) + 0.3560 (R2 = 0.9982). The linear range was from 0.5 to 100 µg·mL-1 and the detection limit (LOD, S/N = 3) was 0.109 µg·mL-1. This non-enzymatic sensor can offer a better alternative to other methods for the analysis of GMP because of cheap cost, low detection limit and good anti-jamming capability in meat quality evaluation.