Self-powered Electronic-skin For Detecting Glucose Level In Body Fluid Basing On Piezo-enzymatic-reaction Coupling Process

The body electric(the integration of flexible biosensors and the human body)has attracted worldwide research attention because of its potential applications in the future health care.Combines biological/chemical sensors with the human body have become possible due to the development of biological science and materials science.The flexible biosensors with miniaturization,high sensitivity,high stability and high life and combines with human body are called electronic skin(e-skin).E-skin has been intensively investigated.But the supplied power of sensors is still a problem.Traditional E-skins require an external power to provide the energy for the normal working.However,e-skin using the battery cannot meet the requirements as the limitation of miniaturization,flexibility and high life.In order to solve the problem,in this paper,we integrate nanogenerators and biosensors in a single device to achieve self-powered e-skin.Specific studies are as follows:(1)A self-powered electronic-skin(e-skin)for detecting glucose level in body fluid has been realized basing on the piezo-enzymatic-reaction coupling process of GOx@ZnO(GOx:glucose-oxidase)nanowire arrays.The e-skin under applied deformation can actively output electric impulse through piezoelectric effect,and the outputting piezoelectric voltage can be significantly influenced by the glucose concentration in the solution.The piezoelectric output can be regarded as both the biosensing signal and the electricity power for driving the device.In this process,the e-skin does not need external electricity power source,and can long-lived work through harvesting the mechanical energy of human motion.The working mechanism has been proposed basing on the coupling of surface enzymatic reaction and piezoelectric effect.A practical application of the e-skin for detecting rabbit blood glucose concentration has been simply demonstrated.The present results could provoke a possible research field for the development of the body electric and widen the study scope for self-powered nano-devices/systems.(2)High and fast response of H2S sensing at room temperature has been realized from NiO/ZnO hetetojunction nanowire(NW)arrays as a self-powered gas sensor.The piezoelectric output generated by NiO/ZnO NW nanogenerator(NG)can act as both the power source and sensing signal.Upon exposure to 1000 ppm H2S at room temperature,the piezo-voltage of NiO/ZnO NW arrays decreases from 0.388 V(in dry air)to 0.061 V,and the response is approximately 10 times higher than that of bare ZnO NW arrays.Such a high performance can be attributed to the piezoelectric effect of ZnO and the conversion of NiO/ZnO PN-junctions.Our study confirms that introducing heterostructures into NG is a right direction for the development of self-powered gas sensors.