G-Optrode Bio-Interfaces for Non-Invasive Optical Cell Stimulation: Design and Evaluation

Abstract

Biocompatibility and potential efficacy in biological applications rely on the bio-interactions of graphene nanoparticles with biological tissues. Analyzing and modulating cellular and device-level activity requires non-invasive electrical stimulation of cells. To address these needs, G-optrodes, bio-interfaces based on graphene, have been developed. These devices use light to stimulate cells without modifying their genetic code. Optoelectronic capabilities, in particular the capacity to transform light energy into electrical energy, will be maintained throughout the procedures of neural stimulation. G-optrodes have also been studied as thin films on a range of substrates, and they have been designed to function at a very small scale. This study examines the impact of G-optrode-based substrate designs on the optical stimulation of pheochromocytoma (PC-12). Graphene electrodes, known as G-optrodes, are responsible for converting light into electrical pulses with stimulating effects. G-optrode bio-interfaces provide a stimulus that is independent of wavelength range but is sensitive to changes in illuminance. The authors have performed a comprehensive investigation based on the correct effects of the medication in vitro, employing substrate-based G-optrode biointerfaces. In substrate-based systems, the authors have proven that graphene is biocompatible. PC-12 cells were cultured on graphene for 7 days. Based on the findings, 20-nm and 50-nm thick G-optrodes are being studied for possible use in biological and artificial retinal applications. The findings of this study highlight the significance of biocompatibility in the selection and use of G-optrodes for biomedical purposes.

Geometrical Optimization and Simulation of NPDA Device for Future Use in Retinal Implant

“…The results obtained for these structures are compared to optimize the device dimensions of NPDA devices with better performance. The sun's light strikes the glass first, then passes through a 50-nm-thick transparent conductive electrode, graphene, and a 100-nmthick active layer, s-SWCNT/C 60 (Moorthy et al, 2022). The last layer is a titanium-based metal electrode with a thickness of 100 nm.…”

“…The objective of the work was to model a multi-disciplinary (multi-physics) organic photovoltaic (OPV) by using mathematical modeling and analyzing the behavior of a standard planar heterojunction. Results show that the performance of organic solar cells is sensitive to the thickness of the photoactive substance (Moorthy et al, 2022). This work mainly focuses on comparing the PHJ and BHJ NPDs for various geometries and optimizing the design to achieve the performance suitable for human subretinal implants.…”

An Integrated Neural Optrode with Modification of Polymer-Carbon Composite Films for Suppression of the Photoelectric Artifacts

“…Optogenetics-based neuromodulation tools are key to the study of neuroscience, which can regulate specific neurons expressing photosensitive proteins through light stimulation and record neuronal responses electrophysiologically with high spatiotemporal resolution. Since the concept of optogenetics was proposed, many researchers have introduced optogenetic tools with different structures for neuroscience research over the past few decades. − The traditional light source coupling optrode, that is, the laser or high-power light-emitting diode (LED) is coupled with the optical fiber as the light source, and the metal wires are used as the recording electrode, or alternatively, an external light source is coupled with the waveguide on a silicon-based substrate. − While this kind of optrode has little damage to the animal brain area, and it relies on an external light source, which will limit the range of animal activity. With the development of semiconductor materials and their processes, integrated LED optrodes have emerged, combining light sources and recording electrodes through semiconductor processes. − In 2015, Wu et al first proposed the concept of fabrication of an integrated four-shank silicon-based probe on a commercial wafer, with each probe containing 12 μLEDs and 32 recording microelectrodes .…”

“…Since the concept of optogenetics was proposed, many researchers have introduced optogenetic tools with different structures for neuroscience research over the past few decades. 1 − 8 The traditional light source coupling optrode, that is, the laser or high-power light-emitting diode (LED) is coupled with the optical fiber as the light source, and the metal wires are used as the recording electrode, or alternatively, an external light source is coupled with the waveguide on a silicon-based substrate. 9 − 12 While this kind of optrode has little damage to the animal brain area, and it relies on an external light source, which will limit the range of animal activity.…”