Glucose Driven Nanobiopower Cells for Biomedical Applications

Abstract

Power supply is an important aspect of micronanobiomedical devices. Implantable devices are required to stay inside of the body for longer period of time to provide continuous monitoring, detection, and therapeutics. The constricted areas of the human body, accessed by these devices, imply that the power source should not increase the payload significantly. Conventional on-board power sources are big, as compared with the device themselves, or involve wire-outs. Both provisions are liable to develop complications for sensor/actuator implant packaging. A plausible approach can be innovative solutions for sustainable bio-energy harvesting. Research studies have reported feasibility of miniature power sources, running on redox reactions. The device design, reported in this study, is a combination of nano-engineered composites and flexible thin film processing to achieve high density packaging. Of which, the end goal is production of energy for sensor applications. Both the bio-electrodes were successfully functionalized by amide bond cross-linkage between the carbon nanotube surface and the enzyme molecules: catalase and glucose oxidase for cathode and anode, respectively. The nanocomposite based biopower cell was evaluated as a steady power supply across the physiological range of glucose concentration. The power cell was able to deliver a steady power of 3.2 nW at 85 mV for glucose concentrations between 3 mM and 8 mM. Electron microscopy scanning of the functionalized electrode surface and spectroscopic evaluation of nanotube surface were used for evaluation of the biofunctionalization technique. Cyclic voltametric (CV) scans were performed on the cathodic and anodic half cells to corroborate bioactivity and qualitatively evaluate the power cell output against the redox peaks on the CV scans. The importance of these results has been discussed and conclusions have been drawn pertaining to further miniaturization (scale down) of the cell.

Integration of biomolecules and nanomaterials: Towards highly selective and sensitive biosensors

“…The most common issue associated with glucose sensors is slow electron transfer to the electrode after glucose oxidation due to inhibition of flavin adenine dinucleotide (FAD) cofactors, which form the redox center of GOx, by the protective glycoprotein shell [37]. Nanomaterial‐based sensor platforms are advantageous in glucose detection using GOx because of the rapid response and the potential for miniaturization [38]. The efficient electrochemical properties of nanotubes offer the ability to enhance the sensitivity and to decrease the response time of glucose sensors by reducing the distance between the redox site and the electrode [39].…”

Flow-induced immobilization of glucose oxidase in nonionic micellar nanogels for glucose sensing

“…The immobilization of GOx has been accomplished by using host matrices such as polymers, [2][3][4][5][6][7] carbon-based materials, [8][9][10][11][12][13][14] and surfactant structures [15][16][17] which are subsequently coated on electrode surfaces. The pH value and the stiffness of polymers and the electron transfer polymerization process add challenges to GOx immobilization.…”

“…6,18,19 With their high surface-to-volume ratios to retain GOx activity, single-walled carbon nanotubes, multi-walled carbon nanotubes, and carbon-based nanomaterials have been used to assemble glucose sensors. [8][9][10][11][12][13][14]20 However, the high cost, unknown biocompatibility, and the complex assembly process make the fabrication of carbon-based glucose sensors difficult. Surfactant structures have gained attention as alternative GOx immobilization substrates to fabricate glucose sensors.…”

“…18 Moreover, the formation of GOx clusters as large as ~1 μm has been observed for polymer-GOx-based glucose sensors. 10,11 We also performed ultraviolet spectrometry to verify GOx encapsulation and investigate the stability and denaturation of GOx in the nanogel. Ultraviolet spectrometry was carried out using a Varian Cary 5000 UV-vis-NIR spectrophotometer coupled with a temperature controller at 25 °C.…”

Wireless power transfer system for a human motion energy harvester

“…In addition, a large number of failures in medical devices are caused by the batteries [6,7]. Suitable sources for human energy harvesting are temperature differences [8], photovoltaic systems [9,10] and glucose fuel cells [11]. Body motion is an abundant source of energy that can work for externally worn and implanted devices alike [12,13,14].…”