Carbon Surface Curvature-Mediated Electronic Fingerprints for Nucleic Acid Base Identification: First-Principles...

Carbon-based nanodevices for bioactive molecular recognition are crucial for biochemical engineering and novel probe development. This is heavily dependent on the surface interaction between the carbon-based nanomaterials (CNMs) and bioactive molecules. However, CNMs with variable topological structures and curvatures can undoubtedly affect the interaction with bioactive molecules such as nucleic acid bases, and the mechanism of carbon surface curvature-mediated electronic fingerprints for nucleic acid base identification has not yet been revealed. This study employs first-principles calculations combined with nonequilibrium Green's function method to investigate the electron transport properties and recognition mechanisms for five bases (A, C, G, T, U) adsorbed onto four CNMs: graphene (GR), graphdiyne (GDY), fullerene C₆₀, and carbon nanotube (CNT). The transport characteristics modulated by carbon surface curvature, including current-voltage curves, transmission spectra, density of states, and band structures, are systematically analyzed. Distinct curvature-sensitivity relationship and voltage-dependent recognition capability are revealed from a material-specific view. It is found that GR can distinguish C/U, and CNTs distinguish C/G and C/T in the high bias range, while GDY and C₆₀ exhibit significant current differences (>1000-2000 μA) at specific voltages (2.5-2.9 V for GDY and ∼2.8 V for C₆₀). The recognition mechanism showed that the curvature-induced band structure modulation in GDY and C₆₀ creates unique transmission channels essential for biochemical identification. GR provides the strongest binding stability of base primarily via dispersion interactions (-13.58 to -18.65 kcal/mol). This study establishes substrate curvature and voltage-tunable electronic signatures as key design parameters for nucleic acid base recognition, providing guidelines for bioactive molecule identification.