Design of a novel optical sensor for the detection of waterborne bacteria based on a photonic crystal with an ultra-high sensitivity

Abstract

Today, detecting processes of waterborne bacteria in drinking water is a global challenge because these bacteria can lead to dangerous diseases to the human body. In this paper, we have developed a new sensor for the detection of waterborne bacteria based on a one-dimensional (1D) defective binary photonic crystal. The defect layer is taken as a water sample located in the middle of the photonic crystal structure. A resonant peak is then created within the photonic bandgap. The sensing mechanism of the proposed detector is based on the refractive index difference between pure water and waterborne bacteria samples. This index change leads to a shift in the resonant peak position in the transmission spectrum. The effects of many parameters, such as incident angle, defect layer thickness, thicknesses of periodic layers and the number of periods on the sensitivity are investigated. At the optimum conditions, the proposed sensor exhibits a sensitivity of 3639.53 nm/RIU which is ultra-high compared with recently published biosensor papers. The proposed design could distinguish between the different types of waterborne bacteria although the minute difference between their refractive indices. In addition to that, it has a simple design so that it can be easily fabricated.

Surface plasmon resonance biosensor based on graphene layer for the detection of waterborne bacteria

“…The resonant angles are found at 54.64°, 56.83° and 58.50° for the samples of pure water, V. cholera and E. coli . The refractive indices of V. cholera and E. coli can be found in reference [24]. The sensitivities are calculated and found as 68.43 and 70.18 °/RIU for the samples of V. cholera and E. coli , respectively.…”

“…The tangential field at the first boundary ( z = 0) and that at the final boundary ( z = z N −1 ) are related to each other through [24]: where F 1 and F N−1 are the tangential electric fields at the first and N th interfaces, respectively, and G 1 and G N −1 are the tangential magnetic fields at the first and N th interfaces, respectively. For the j th layer, the characteristic matrix ( P j ) is given by: is the phase variation of the light wave propagating through the j th layer which is given by [24]: where and d j are the dielectric permittivity and thickness of the j th layer. are the incident light wavelength, the angle of incidence and the prism refractive index.…”

“…α j is the phase variation of the light wave propagating through the jth layer which is given by [24]:…”

“…For each layer, the dielectric constant and the thickness are ε k and d k , respectively. The tangential field at the first boundary (z = 0) and that at the final boundary (z = z NÀ1 ) are related to each other through [24]:…”

A Theoretical Approach for Detecting the Chikungunya Virus Based on 1D Photonic Crystals

“…SiC has an RI of 2.6667 [49] and SiO 2 has an RI of 1.4599, which are calculated from the Sellmeier equations, [43,47] and the RI of the substrate, such as crown glass, is 1.517. [46] n SiO 2 ¼ ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffi The RI of the blood samples ranges from 1.33 to 1.72; consequently, all of the geometrical parameters were chosen after a careful optimization process to get a broader bandgap. It is observed from Figure 2 that the bandwidth of the PBG is 715 nm, appearing between the wavelength ranges of 1839 and 2554 nm.…”