A self-powered glucose biosensing system

Abstract

A self-powered glucose biosensor (SPGS) system is fabricated and in vitro characterization of the power generation and charging frequency characteristics in glucose analyte are described. The bioelectrodes consist of compressed network of three-dimensional multi-walled carbon nanotubes with redox enzymes, pyroquinoline quinone glucose dehydrogenase (PQQ-GDH) and laccase functioning as the anodic and cathodic catalyst, respectively. When operated in 45mM glucose, the biofuel cell exhibited an open circuit voltage and power density of 681.8mV and 67.86µW/cm2 at 335mV, respectively, with a current density of 202.2µA/cm2. Moreover, at physiological glucose concentration (5mM), the biofuel cell exhibits open circuit voltage and power density of 302.1mV and 15.98µW/cm2 at 166.3mV, respectively, with a current density of 100µA/cm2. The biofuel cell assembly produced a linear dynamic range of 0.5–45mM glucose. These findings show that glucose biofuel cells can be further investigated in the development of a self-powered glucose biosensor by using a capacitor as the transducer element. By monitoring the capacitor charging frequencies, which are influenced by the concentration of the glucose analyte, a linear dynamic range of 0.5–35mM glucose is observed. The operational stability of SPGS is monitored over a period of 63 days and is found to be stable with 15.38% and 11.76% drop in power density under continuous discharge in 10mM and 20mM glucose, respectively. These results demonstrate that SPGSs can simultaneously generate bioelectricity to power ultra-low powered devices and sense glucose.