Amperometric Glucose Sensing at Nanomolar Level Using MOF-Encapsulated TiO2 Platform

A new synthetic approach is established where both TiO2 nanoparticles and glucose oxidase (GO(x)) are together encapsulated into the cavity of ZIF-8 metal-organic framework (MOF) to fabricate a mediator-free glucose sensor in aqueous media. ZIF-8 possesses high stability both physically and chemically. Moreover, its large surface area and tunable cavity size are supportive to encapsulate both nanoparticles (TiO2) and enzymes (GO(x)). The as-synthesized nanocomposite is methodically characterized by various advanced analytical techniques, which suggests that TiO2 is uniformly distributed within the cavity of ZIF-8 MOF. High surface area and double-layer capacitance of nanostructured TiO2 jointly enhance the catalytic biosensor activity. The as-synthesized nanocomposite exhibits commendable stability and is able to detect low-level concentration (80 nM) of glucose in aqueous media by utilizing very low concentration of GO(x) (62 mu g in 1 mL).