MATLAB Simulation-Based Theoretical Study for Detection of a Wide Range of Pathogens Using 1D Defective Photonic Structure

A F Amin,M A Mohaseb,S K Awasthi,Arafa H Aly,Z S Matar

doi:10.3390/cryst12020220

Abstract

The present 1D photonic biosensor is composed of two sub-PhCs of alternate layers made of GaP and SiO2. The period number of each PhC has been fixed to 3. Both these PhCs are joined together through a cavity region of air in which different analytes are to be filled one by one under the scope of this study. The theoretical findings of this work have been formulated with the help of the well-known transfer matrix method. Moreover, all the computations pertaining to this work have been carried out with the help of MATLAB software. The effect of change in cavity thickness and angle of incidence corresponding to a TE wave on the transmittance of the structure (AB)ND(AB)N has been studied theoretically which in turn determines the performance of the proposed biosensor. Various parameters, such as sensitivity (S), signal to noise ratio (SNR), figure of merit (FOM), resolution (RS), detection limit (LOD), quality factor (Q) and dynamic range (DR) have been theoretically calculated to evaluate the performance of the proposed design in true sense. The sensitivity of this structure varies between the highest and lowest values of 337.3626 nm/RIU and 333.0882 nm/RIU corresponding to water samples containing Pseudomonas aeruginosa cells and Bacillus anthracia cells, respectively, under normal incidence condition with a cavity thickness of 2.0 µm. The resolution (in nm) and LOD (in RIU) values of the proposed design are small enough and are significant for our structure. This study may also be helpful for distinguishing various microbiological samples under investigation and find suitable applications for discriminating bacterial cells from spores.

Highlights

In the recent years, a lot of attention has been paid to ensure food and drinking water safety worldwide
It is a well-known fact for decades that Escherichia coli cells and their human hosts may simultaneously survive in good health due to the mutual benefits of each other [9]
Motivated by the abovementioned excellent sensing capabilities of photonic biosensors, in this paper, we have explored one of the possible ways by which a 1D photonic crystal (PhC) with defect can be efficiently used to detect bacterial cells and spores in different samples under investigation

Summary

Introduction

A lot of attention has been paid to ensure food and drinking water safety worldwide. Pathogenic microbes are effortlessly surviving in food and drinking water which may create several health-related problems, such as hepatitis A & E, cholera, and cryptosporidiosis [1,2]. The consumption of contaminated food and/or drinking water [1,2] may cause severe kinds of gastrointestinal tract infections in the human body. Bacillus anthracis cells are responsible for resilient and deadly infections, such as anthrax which is a kind of bacterial pathogen [11,12,13]. These pathogens may become the root cause of developing spores in the human body [12,13,14]. An analytical approach demonstrating a novel chemical sensor by using 1D DPhC has been proposed by Adl et al The geometry of this chemical sensor is based on total internal reflection in which a cavity has been created at the end of the structure [19]

Methods

Results

Conclusion