Nanomaterial‐Integrated Fiber Neural Probes for Deep Brain Monitoring and Modulation: Challenges and Opportunities

Understanding the molecular and thermal dynamics of the brain is critical for advancing neuroscience and developing targeted therapies for neurological disorders. However, capturing these processes in deep brain regions remains challenging due to the need for tools that are sensitive, multifunctional, minimally invasive, and operable under complex physiological conditions. This perspective highlights the potential of nanomaterial-integrated fiber neural probes as versatile platforms for deep brain molecular sensing, photothermal neural stimulation, and temperature monitoring. By combining the light-guiding capabilities of optical fibers with the functional advantages of nanomaterials, these probes enable real-time, high-performance brain interrogation. The discussion begins with surface-enhanced Raman scattering (SERS)-based fiber probes, which use plasmonic nanostructures for label-free, ultrasensitive detection of neurotransmitters and biomolecules. Key technical challenges, including mechanical stability, biocompatibility, and molecular specificity, are addressed alongside recent advances in nanofabrication and surface engineering. The integration of thermoplasmonic materials and upconversion nanoparticles is then explored for localized stimulation and temperature sensing via luminescent thermometry, also discussing the potential for closed-loop neuromodulation through combined heat generation and real-time thermal feedback. These emerging technologies represent a promising frontier in minimally invasive neural interfaces, with strong potential to transform brain monitoring and modulation in both research and clinical settings.