Development of Surface Plasmon Resonance Sensor for Detecting Food Preservatives

Abstract

Food preservatives and adulteration is the universal concern of recent days. Particularly, developing states are the main maltreated with food contamination and it is a thoughtful problem in recent years. Formalin is a chemical compound that commonly present in food used for the preservation. Its frequent and illegal addition with food is a danger for human health and psychology. The recurrent ingesting of formalin contaminated food causes uncompromising health sicknesses. This critical issue causes fatal disease like chronic cancer. Therefore, identification of formalin in food is an extreme need, which is becoming a general problem in emerging countries.

In this dissertation, formalin is detected quantitatively by designing a Graphene-MoS2 amalgamated 2D nano sheets with a TiO2-SiO2 nano-layered surface plasmon resonance (SPR) based sensor. This sensor distinguishes the presence of formalin utilizing the attenuated total reflection (ATR) approach and inspecting the reflectance vs SPR angle and transmittance vs surface plasmon resonance frequency (SPRF) attributes. Analytical approach for analyzing the sensor performance parameters has been carried out using MATLAB commercial software. The quantitative effect analysis of individual and amalgamated Graphene-MoS2 with TiO2-SiO2 layers has been studied for sensitivity, detection accuracy and quality factor. In addition, optimization of Silver layer thickness is carried out for sensitivity, detection accuracy and quality factor individually.

Electric field distribution through the sensor has been investigated and analyzed by using YEE algorithm on the Lumerical FDTD solution commercial software.

An alternative composite layer sensor structure has also been designed and developed in a configuration of Graphene-PtSe2-Ag-ZnO with BK7 glass prism. Formalin is detected successfully using this sensor structure by angular investigation method. The performance of this alternative sensor structure for formalin detection has been analysis analytically and it shows an outperform with very high sensitivity.

A comparative study among the performance of different composite sensor structure and the proposed sensors are also presented. Another comparison has been carried out between the existing sensor structures and the proposed sensor structures. This is the silver integrated composite sensor that shows highest performance reported by SPR technology. Finally, recommendations for additional research has been anticipated.