Plasma-programmed nanographene charge-transfer interfaces for SERS and redox catalysis

Nanographene has emerged as a versatile platform for charge-transfer-driven sensing and catalysis due to its tunable electronic structure, high surface sensitivity, and rich interfacial chemistry. In this review, we present a unified perspective on how structural modulation, including edge engineering, defect regulation, heteroatom incorporation, and surface functionalization, governs charge transfer (CT) junctions in nanographene and determines their interfacial behavior. It connects them through a processing-structure-charge-transfer-function framework in which plasma conditions are treated as upstream programming variables, while charge-transfer junctions provide the common mechanistic basis linking interfacial structure to sensing and catalytic outcomes. Particular emphasis is placed on plasma-enabled approaches as non-equilibrium strategies for programming nanographene interfaces under relatively mild conditions, enabling precise control over defect density, coordination environments, and electronic asymmetry. We further discuss how these programmed interfaces modulate the local density of states, band alignment, and interfacial charge redistribution, with direct implications for molecular adsorption, catalytic intermediate stabilization, and reaction selectivity. Surface-enhanced Raman scattering (SERS) is an interfacial readout method for probing CT processes, particularly in hybrid systems, where chemical enhancement is closely linked to electronic coupling. In addition to sensing, catalytic redox reactions at programmed nanographene interfaces are examined, including oxidase-like catalysis, oxygen activation, and oxygen reduction pathways mediated by atomically dispersed and heteroatom-doped active sites. Overall, this review establishes plasma-programmed nanographene as a promising material platform for integrating charge-transfer-driven functionality, mechanistic interfacial insights, and programmable synthesis for next-generation sensing and catalytic applications.