Design of porous Si-cavity as highly efficient SERS active substrate for reproducible and accurate detection of bacteria

We propose a novel methodology of passively trapping bacteria in suspension using a Silicon micro-cavity (SiC) chip of suitable dimensions and investigated the plasmonic enhancement of bacteria having various sizes and refractive indices using the three-dimension finite difference time domain (3D-FDTD) simulations. The design employs a simplified method with spherical or rod-shaped bacterial structures with a uniform refractive index at the surface. The investigation of various laser wavelengths (532nm and 785nm) and the amount of plasmonic enhancement is systematically explored considering 60nm diameter of silver (Ag) and gold (Au) nanoparticles (NPs) that enables the proposed methodology to be applicable in real and practical applications.