One-dimensional defective photonic crystal as a high-performance sensor for bacterial water-borne

Abstract

The present work deals with photonic sensing technology used for biosensing applications. In this paper we have theoretically examined the transmission properties of one-dimensional (1D) defect photonic crystal (DPC) suitable for biosensing applications. The number of contaminated water samples containing different types of bacteria is poured into the defect layer region and corresponding change in the transmission peaks of defect mode inside photonic bandgap (PBG) has been observed. The proposed structure is composed of two sub-photonic crystals (PCs) containing Si and TiO2 material layers. These two sub-PCs are separated by defect layer of air in which various sensing samples has to be poured one by one. The performance of the proposed biosensor is verified by measuring redshift in the central wavelength of defect mode inside PBG depending upon the change in refractive index of various water borne bacteria samples from 1.333 to 1.43. The sensitivity of the proposed biosensor reaches to high value of 483.6 nm/RIU for Escherichia coli (E. coli) bacteria sample. The proposed biosensor achieves high value of figure of (FOM) of order 104 and low value of limit of detection (LOD) of order 10− 6 which makes our biosensor suitable for biosensing applications.