Modeling and analysis of a microresonating biosensor for detection of Salmonella bacteria in human blood.

Mahdi Bahadoran,Jalil Ali,Muhammad Aziz,Ahmad Noorden,Faeze Mohajer,Shahrin Hashim,Preecha Yupapin,Kashif Chaudhary

doi:10.3390/s140712885

Abstract

A new photonics biosensor configuration comprising a Double-side Ring Add-drop Filter microring resonator (DR-ADF) made from SiO2-TiO2 material is proposed for the detection of Salmonella bacteria (SB) in blood. The scattering matrix method using inductive calculation is used to determine the output signal's intensities in the blood with and without presence of Salmonella. The change in refractive index due to the reaction of Salmonella bacteria with its applied antibody on the flagellin layer loaded on the sensing and detecting microresonator causes the increase in through and dropper port's intensities of the output signal which leads to the detection of SB in blood. A shift in the output signal wavelength is observed with resolution of 0.01 nm. The change in intensity and shift in wavelength is analyzed with respect to the change in the refractive index which contributes toward achieving an ultra-high sensitivity of 95,500 nm/RIU which is almost two orders higher than that of reported from single ring sensors and the limit of detection is in the order of 1 × 10−8 RIU. In applications, such a system can be employed for a high sensitive and fast detection of bacteria.

Highlights

Salmonella Typhimurium bacteria which cause thypoid fever contain flagellin
Most biosensors are focused on the label-free biosensing detection of bacterial proteins such as quartz crystal microbalance (QCM), surface plasmon resonance (SPR), coupled plasmon-waveguide resonance (CPWR)
Add-drop Filter microring resonator (DR-add-drop filter (ADF)) made from SiO2-TiO2 material is proposed for the detection of Salmonella bacteria (SB) in blood

Summary

Introduction

Salmonella Typhimurium bacteria which cause thypoid fever contain flagellin (a protein with 494 amino acids of spherical shape, found in transparent filament cylinders). The optoelectronics biosensor based on a microresonator in a photonics circuit has been introduced in the biosensing field as an important device that provides the high efficiency in biomolecule detection [1]. We achieve an ultra-high sensitivity detection of 95,500 nm/RIU and a very low limit of detection in the order of 1 × 10−8 RIU, which are almost two orders better than those reported for single ring sensors. In applications, such a system can be employed for a high sensitive and fast detection of bacteria. The main advantage of our proposed sensor is that it satisfies both intensity and wavelength interrogation approaches in comparison with other optical sensors and can be employed for a high sensitive and fast detection of Salmonella bacteria

Sensor Layout

C2 iS2 E2

Results and Discussion