Theoretical insights of silicene doped with transition metals as C - reactive protein biosensors for cardiac vascular applications using density functional theory.

Early and accurate detection of C-reactive protein (CRP), a key biomarker for inflammation and cardiovascular conditions, remains a critical need in medical diagnostics. In this study, we employ density functional theory calculations using the B3LYP functional in Gaussian 16 to explore the CRP sensing potential of silicene doped with iron and nickel atoms at central and edge sites. Using density functional theory with the B3LYP functional in Gaussian 16, we systematically analyze the adsorption behavior, thermodynamic stability, and electronic response of CRP-bound systems. Adsorption energy and thermodynamic parameters confirm spontaneous and exothermic interactions, with the iron doped at center configuration exhibiting the strongest adsorption and highest charge transfer. The interaction of CRP induces pronounced changes in the electronic structure, including energy gap modulation, Fermi level shifts, and enhanced density of states near the Fermi level, indicating improved electronic sensitivity. Comparative analysis shows that the nickel doped at edge configuration also exhibits significant responsiveness, with an adsorption energy and energy gap change. Furthermore, non-covalent interaction plots reveal strong van der Waals interactions between CRP and the doped silicene surfaces, confirming favorable adsorption mechanisms. These combined insights from electronic structure, thermodynamic, and interaction analyses establish that the iron doped at center of silicene and nickel doped at edge of silicene configurations might act as promising candidates for next-generation CRP biosensors based on two-dimensional materials.