Recording Neural Activity Based on Surface Plasmon Resonance by Optical Fibers-A Computational Analysis

Abstract

An all optical, non-destructive method for monitoring neural activity has been proposed and its performance in detection has been analyzed computationally. The proposed method is based on excitation of Surface Plasmon Resonance (SPR) through the structure of optical fibers. The sensor structure consists of a multimode optical fiber where, the cladding of fiber has been removed and thin film of gold structure has been deposited on the surface. Impinging the laser light with appropriate wavelength inside the fiber and based on the total internal reflection, the evanescent wave will excite surface plasmons in the gold thin film. The absorption of light by surface plasmons in the gold structure is severely dependent on the dielectric properties at its vicinity. The electrical activity of neural cells (action potential) can modulate the dielectric properties at its vicinity and hence can modify the absorption of light inside the optical fiber. We have computationally analyzed the performance of the proposed sensor with different available geometries using Finite Element Method (FEM). In this regard, we have shown that the optical response of proposed sensor will track the action potential of the neuron at its vicinity. Based on different geometrical structure, the sensor has absorption in different regions of visible spectrum.

Biosensors for Epilepsy Management: State-of-Art and Future Aspects

“…The neural activity (action potential) can modulate the dielectric properties as well as SPR of the metal surface and absorbance of light in the optical fiber. Based on the different geometrical structure of the brain, the sensor show absorption in the different region of visible spectrum [109]. The detection of an epileptogenic focus can be non-invasively performed by NIR.…”

Surface-Enhanced Raman Scattering Nanosensing and Imaging in Neuroscience

“…In addition to SERS discussed in the preceding sections, other plasmonics techniques based on surface plasmon resonance (SPR) − and localized surface plasmon resonance (LSPR) − offer several advantages in nanosensing for neuroscience such as high sensitivity, biological compatibility, label-free analysis, and real-time detection. For neurotransmitter detection, the coupling of the localized and surface plasmon has been shown to be highly sensitive for the detection of DA in aCSF to reach LODs as low as 10 –12 M .…”

Single-cell micro- and nano-photonic technologies

“…The system was validated in vivo in mouse visual cortex, and even though multiple cells were elicited during the experiments spatial selectivity could be improved by accurate delivery of both light and carbon probes. On the other hand, the refractive index dependent wavelength shift of SPR of an Au film deposited on optical fibers can be exploited to record neural activity in vivo without the needs of Ca 2+ or voltage fluorescent reporters [104,105].…”