A nanohybrid-based smartphone-compatible high performance electrochemical glucose sensor

A cost-effective and low-potential smartphone-compatible electrochemical sensor was constructed using a nanohybrid for the sensing of glucose in human and animal serum. The nanohybrid composed of gold nanoparticle (GNP) decorated cobalt hexacyanoferrate (CHCF) modified ZIF-67 (cobalt metal organic framework, CMOF) was synthesized and characterized by FTIR, XRD, and SEM with EDX analysis. The electrochemical characteristics of the nanohybrid were investigated by depositing the nanohybrid over a conventional glassy carbon electrode (GCE) and performing cyclic voltammetry, which revealed a stable redox peak with a formal potential of +0.23 V, corresponding to Co redox couple in GNP–CHCF–CMOF. Thus, developed sensor was utilized for the electrochemical glucose detection, which showed exceptional electrocatalytic activity over a linear detection range from 8.33 to 3793 μM with a low detection limit of 0.96 μM at a low potential of +0.35 V. Furthermore, the GNP–CHCF–CMOF/GCE sensor was employed for the detection of glucose spiked in human and rabbit serum samples, which showed excellent recoveries. A portable measurement device was fabricated which showed the real-time monitoring of glucose in a smartphone. This novel approach paves the way for the design and fabrication of cost-effective, low-potential sensors, which would reduce overall costs and enhance the performance of sensing devices.