Neuroplasmonics for Brain Interfaces: Plasmonic Neurophotonics From Neurochemical Sensing and Neuromodulation to Quantum‐Biological Probing

ABSTRACT Plasmonic neurophotonics, the integration of plasmonic nanostructures with neural interfaces, is emerging as a powerful paradigm for neuroscience and neuro‐engineering. By exploiting surface plasmon resonances in metallic nanostructures, this approach enables capabilities previously unattainable with conventional neurotechnologies. These include label‐free single‐molecule neurochemical sensing (e.g., via surface‐enhanced Raman spectroscopy, SERS), sub‐cellular neuromodulation through highly localized photothermal or photoelectric stimulation, and super‐resolved imaging of neural circuitry beyond the diffraction limit. We provide a comprehensive review of the physical underpinnings of plasmon–neuron interactions and the diverse device architectures (from plasmonic fiber‐optic probes to gap‐enhanced nanoantennas) that leverage extreme field localization for neural applications. We also bridge this field with emerging quantum biology, discussing how quantum effects in plasmonics (tunneling currents, charge‐transfer plasmons, etc.) can be harnessed to probe and manipulate neural processes at the nanoscale. Key challenges, such as biocompatibility, thermal management, and quantum decoherence in living systems, are identified, along with material and design strategies to address them. The synthesis of plasmonics, neurophotonics, and quantum science outlined here underscores the timeliness and transformative potential of neuroplasmonics in next‐generation brain research and therapeutics.