Biosensors for Identifying Hazardous Adulterants in Edibles

Food contamination (particularly in daily edible items like milk, oil, yogurt, etc.) is a common practice in developing countries to make more money and to meet the excessive demand (with low-cost). Since most of such adulterations are made by illiterate people who are unaware of hazardous health effects associated with such contaminations, consuming such impure food can result in various dangerous health effects. Though government regulatory authorities have detection mechanisms, they are not only expensive (with general spectroscopic analysis) but also inaccessible for domestic users for daily usage. Owing to such situation, there is a definite need for a portable and straightforward detection mechanism for domestic users to avoid serious health issues. In this paper, we present all-dielectric meta-biosensors to identify (both qualitatively and quantitatively) the hazardous adulterants in water and milk via refractive index sensing. Our demonstrated platform is a highly efficient and unique way of testing water and milk with numerically calculated sensitivity of ~ 500nm/RIU, a change in response of transmittance per refractive index unit is ~ 8 (800 %) and a figure of merit (FoM) of ~ 14.7. The proposed single wavelength transmittance based measurement could remarkably decrease the cost and the size of sensing platform without compromising sensitivity. Our demonstrated silicon-based design provide a route to realize various highly efficient and affordable sensors for qualitative and quantitative analysis of different food contaminants.