Theoretical study of one-dimensional defect photonic crystal as a high-performance sensor for water-borne bacteria

The present work deals with the photonic sensing technology used for biosensing applications. In this paper we have examined the transmission properties of one-dimensional defect photonic crystal 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 has been observed. The proposed structure is composed of two sub-photonic crystals containing Si and TiO2 material layers. These two sub-PCs are separated by the 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 the 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 bacteria sample. The proposed biosensor achieves a high value of figure of merit of order 10(4) and low value of limit of detection of order 10(-6) which makes our biosensor suitable for biosensing applications.

Automated summary

This work examines the transmission properties of one-dimensional defect photonic crystal suitable for biosensing applications. By observing the change in transmission peaks of defect mode inside photonic bandgap caused by different water-borne bacteria samples, the performance of the proposed biosensor is verified, showing high sensitivity and figure of merit suitable for biosensing applications.