# NIR‐Triggered Upconversion‐Perovskite Heterostructures for Non‐Genetic, Implant‐Free Optoelectronic Neuromodulation

## TL;DR

A new optoelectronic method uses near-infrared light to modulate brain activity without implants or genetic modifications.

## Contribution

A non-genetic, implant-free neuromodulation platform using NIR-triggered upconversion-perovskite heterostructures is introduced.

## Key findings

- NIR illumination of the heterostructure increases firing rates of wild-type dopaminergic neurons in brain slices.
- Transcranial NIR stimulation modulates neuronal activity and promotes dopamine release in vivo.
- The heterostructure shows negligible neuroinflammation and structural stability over four weeks in brain tissue.

## Abstract

Optoelectronic neuromodulation has transformed neuroscience research and holds great promise for treating neurological disorders. However, conventional optoelectronic methods rely on ultraviolet/visible light, which poorly penetrates tissue and typically necessitates surgically implanted optical fibers for deep‐brain stimulation. Here, a heterostructure is presented that integrates near‐infrared (NIR)‐excitable upconversion nanoparticles (UCNPs) and broadband‐absorbing CsPbBr3 perovskite quantum dots (QDs). This nanostructure converts deeply penetrating 980 nm NIR light into localized electrical stimuli, enabling immediate and precise modulation of neuronal activity without implants. In vitro, NIR illumination of this heterostructure reliably increases the firing rate of wild‐type dopaminergic (DA) neurons in acute brain slices. Importantly, in vivo, transcranial NIR stimulation of the heterostructure in the secondary motor cortex (M2) and ventral tegmental area (VTA) modulates neuronal activity, triggers turning behavior, and promotes dopamine release. Moreover, it exhibits negligible neuroinflammation and structural stability in brain tissue over at least four weeks. By integrating a stable heterostructure for efficient NIR‐driven photocurrent generation, the method offers a non‐genetic, minimally invasive platform for precise neuromodulation in wild‐type animals.

The Single‐Nanostructured Optoelectronic Vehicle for neuromodulation Activation (SNOVA) establishes a paradigm for non‐genetic, implant‐free neuromodulation. By integrating NIR‐excitable UCNPs with broadband‐absorbing perovskite QDs, SNOVA efficiently converts deeply penetrating light into localized electric fields that modulate neuronal ion dynamics, trigger behavioral responses, and enable precise, minimally invasive deep‐brain modulation.