Design fabrication of electrochemical sensor based on Ru(bpy)/SMWCNTs/Au/GCE electrode for the selective determination of 5'-guanosine monophosphate.

5'-Guanosine monophosphate (5'-GMP) is one main source of freshness in broths. Herein, an electrochemical platform based on a novel ternary nanocomposite glassy carbon electrode modified with advantageously-united gold nanoparticles, 2,2'-bipyridine hydrated ruthenium (Ru(bpy)Cl) and sulfonated multi-walled carbon nanotubes (SMWCNTs)was prepared and used to detect 5'-GMP. After conditions optimization, the best performance of the electrochemical sensor was found in acidic media, including high specificity, sensitivity and selectivity. The electrochemical sensor exhibited a wide linear range under the optimal conditions. The enhanced sensitivity of this sensor was attributed to the Ru(bpy)Cl and functionalized SMWCNTs that provided high electrical conductivity and electrocatalytic properties during electrochemical reaction. Precise analysis of 5'-GMP in actual broth samples showed satisfactory recovery. Thus, the sensor can be used in the market and food enterprises.