<p>This article presents and simulates a dielectric-modulated Negative Capacitance Fin-Field Effect Transistor (DM-NC-FinFET). The proposed DM-NC-FinFET device have semiconductor like silicon (Si) and dielectric like Silicon dioxide (SiO₂), Titanium dioxide (TiO₂) and Hafnium dioxide (HfO₂). The high-K HfO₂ is used as NC layer to achieve internal voltage enhancement and TiO₂ is used as high-K dielectric to get better electrostatic control and reduced leakage currents. Here, a cavity is formed at both sides of the source and drain of the TiO₂ dielectric to detect biomolecules such as Streptavidin (K = 2.1), Biotin (K = 2.63), Ferro-cytochrome (K = 4.7), Bacteriophage T7 (K = 6.3), and Gelatin (K = 12). The raised source-drain (RSD) architecture provides a larger cavity volume for biomolecule interaction, thereby enhancing the biosensor sensitivity and selectivity. In this NC-FinFET, incorporating two different gate materials to strengthen the gate-channel coupling. The sensing capability of the proposed device has much better performance through optimized gate engineering, Fin geometry, and cavity design each of this contributes to stronger electrostatic control and better biomolecule channel interaction. While the dielectric constant of biomolecules varies from 1 to 12, both the drain current and sensitivity change considerably. The biosensor effectively detects neutral, negatively charged and positively charged biomolecules, achieving a sensitivity of 1.74 × 10³, 1.78 × 10³ and 1.74 × 10³, respectively. All simulations were performed in the Silvaco ATLAS TCAD (3D) environment with well calibrated device structure for accurate and reliable performance evaluation. These features make NC-FinFET based biosensor suitable for high sensitivity biosensing.</p>