Flexible Optogenetic Transducer Device for Remote Neuron Modulation Using Highly Upconversion‐Efficient Dendrite‐Like Gold Inverse Opaline Structure

Abstract

A remote optogenetic device for analyzing freely moving animals has attracted extensive attention in optogenetic engineering. In particular, for peripheral nerve regions, a flexible device is needed to endure the continuous bending movements of these areas. Here, a remote optogenetic optical transducer device made from a gold inverse opaline skeleton grown with a dendrite-like gold nanostructure (D-GIOF) and chemically grafted with upconversion nanoparticles (UCNPs) is developed. This implantable D-GIOF-based transducer device can achieve synergistic interaction of the photonic crystal effect and localized surface plasmon resonance, resulting in considerable UCNP conversion efficiency with a negligible thermal effect under low-intensity 980 nm near-infrared (NIR) light excitation. Furthermore, the D-GIOF-based transducer device exhibits remarkable emission power retention (≈100%) under different bending states, indicating its potential for realizing peripheral nerve stimulation. Finally, the D-GIOF-based transducer device successfully stimulates neuronal activities of the sciatic nerve in mice. This study demonstrates the potential of the implantable device to promote remote NIR stimulation for modulation of neural activity in peripheral nerve regions and provides proof of concept for its in vivo application in optogenetic engineering.

Light Conversion Nanomaterials for Wireless Phototherapy

“…6 There is increasing interest in delivering UCNPs chemically or physically grafted onto small devices or tubes that aim to change the motor and learning behavior in freely moving animals in the field of optogenetics. 60 Recent UCNPsmediated optogenetics studies are summarized in Table 1.…”

Achieving Functionality and Multifunctionality through Bulk and Interfacial Structuring of Colloidal-Crystal-Templated Materials

“…The internal surface of 3DOM gold was modulated by electrochemical treatment with dopamine hydrochloride as a reducing agent to achieve cluster-like, particle-like, and dendritelike surface morphologies. 133 After covalent attachment of upconversion nanoparticles to the modified 3DOM gold surfaces, the material with dendrite-like surface structure exhibited considerable upconversion efficiency when irradiated with near-infrared light due to the effect of the photonic crystal structure on localized surface plasmon resonance. These effects remained even when the composite material was embedded in a PDMS matrix to fabricate a flexible optogenetic transducer.…”

“…The complexity of a 3DOM device that relies on localized surface plasmon resonance can be increased even more as illustrated in the following example of a biomedical application. The internal surface of 3DOM gold was modulated by electrochemical treatment with dopamine hydrochloride as a reducing agent to achieve cluster-like, particle-like, and dendrite-like surface morphologies . After covalent attachment of upconversion nanoparticles to the modified 3DOM gold surfaces, the material with dendrite-like surface structure exhibited considerable upconversion efficiency when irradiated with near-infrared light due to the effect of the photonic crystal structure on localized surface plasmon resonance.…”

Optoelectronic Neural Interfaces Based on Quantum Dots

“…Numerous studies in these areas enabled efficient and biocompatible UCNP systems. Particularly, their efficient use in neural modulation has been investigated as the visible photon sources required by optogenetics. − Moreover, plasmonic nanostructures have been utilized to enhance upconversion efficiency , and their stand-alone use was also studied for modulation of neural activity. , Therefore, hybrid systems of UCNPs, photoactive polymers, and plasmonic nanostructures with QDs can offer numerous advantages and opportunities for wireless in vivo studies and clinical research.…”