Frontiers in Bioscience-Landmark (FBL) is published by IMR Press from Volume 26 Issue 5 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.
This paper concentrates on recent developments in microsensors and microbiosensors for the possible applications in visual prostheses, especially retinal prosthetic devices. A brief introduction on the developments of visual prosthesis will be presented. The importance for in-vivo pH measurements as well as the need for an implantable pH sensor will be demonstrated. Electrochemical biosensors developed for sensitive measurements of glucose and L-glutamate, a known neurotransmitter in the retina and brain will be reviewed. Novel electrode materials such as chemically modified thin-film diamond in applications for implantable biosensors will be shown. The challenges in the development of chronic implantable sensor systems, especially using MEMS technology for medical implants, will be discussed.