Gold Nanomaterial-Enabled Optical Neural Stimulation

Abstract

Gold nanomaterials, including cylindrical nanorods, spherical nanoparticles, nanostars, and nanoshells, transduce light to heat due to localized surface plasmon resonance (LSPR). Once targeted to neurons, they can, therefore, serve as nano-antennae receiving light and generating heat, and the local temperature rise can modulate neural activities by activating temperature-sensitive ion channels and/or altering plasma membrane’s capacitance. Due to their high photothermal transduction efficiency, genetic modification on neurons is usually unnecessary to enable an adequate cellular response. Additionally, gold nanomaterials can be surface modified and specifically targeted to neurons, improving the spatial resolution. Furthermore, their LSPR wavelength can also be tailored to be within the biological window, and the nanomaterials can be made to an injectable form, together significantly lowering the invasiveness. These features plus their excellent biocompatibility make gold nanomaterial-enabled optical stimulation a valuable alternative to conventional electrical stimulation, direct optical stimulation, and optogenetics. In this chapter, the development of gold nanomaterial-enabled optical neural stimulation is introduced with special emphasis on the critical design factors and challenges.