Ultrasensitive detection of rutin antioxidant through a magnetic micro-mesoporous graphitized carbon wrapped Co nanoarchitecture

Abstract Ultrasensitive sensing of organic compounds has attracted a great deal of attention in recent years. Here, we report air-stable cobalt decorated-nanoporous carbon (Co/ZIF-C), derived from the pyrolysis of zeolitic imidazolate based metal-organic framework (ZIF-67), for ultrasensitive detection of flavonoid, rutin. In line with this, we examined the electrosensing activity of Co/ZIF-C in the presence of rutin and found that it could be a promising agent for sensing of formaldehyde, toluene and hydrogen gases. In the structure of Co/ZIF-C, Co synergizes the sensing performance and hence, shows a superior activity compared to the commercially available forms of carbon nanostructures (e.g. carbon nanotube (CNT) and graphene). The designed sensor, Co/ZIF-C/GCE (GCE, glassy carbon electrode), exhibits sensitivity ca 2.5, 1.5, 22.6 and 125.0 times more than the Co-etched Co/ZIF-C, SWCNT/GCE, rGO/GCE and bare GCE, respectively. The linear range, quantification (LOQ) and detection (LOD) limits of rutin sensor with Co/ZIF-C/GCE were found to be 0.1–30 μM, 73 and 22 nM, respectively. The Co/ZIF-C/GCE sensor is demonstrated to be highly selective toward rutin in the presence of other interfering ions, biomolecules and antioxidants. In addition, the newly developed electrochemical technique was approved by HPLC to determine rutin antioxidant in mixed vitamin tablet samples.