Glycoconjugates coated gold nanorods based novel biosensor for optical detection and photothermal ablation of food borne bacteria

Abstract

Foodborne bacterial species have been identified as the major cause in most of the severe pathogen related diseases. Conventional methods like plating and enzyme-linked immunosorbent assay (ELISA) are time overriding and laborious. Fast detection of bacterial species in food is a proximate obligation to guarantee food safety. Nanotechnology has emerged as a great field in case of rapid detection of pathogens in recent years. In the present work, gold nanorods, (AuNRs) based sensor was developed for swift and sensitive detection of foodborne bacteria. AuNRs has good electro-optical properties due to its Near-Infrared (NIR) absorption and scattering in surface plasmon resonance (SPR) wavelength regions. By exploiting the sugar based adhesion properties of bacteria, the sugar capped AuNRs can be used as potential nanobiosensor to detect the food borne bacteria. Polyethylene glycol (PEG) coated AuNRs were covalently functionalized with different types of amine terminated sugar using EDC coupling reaction. The sensitivity of synthesized nanobiosensor was probed by lectin binding assay and also with food borne bacteria (Escherichia coli) by using spectrophotometric and microscopic techniques. Pseudomonas aeruginosa was also used to probe the specificity of our synthesized biosensor through lectin-sugar interaction. Due to the specific interaction of sugar coated probe with foodborne bacteria, our nanoprobe has shown significant and selective photoablation of targeted bacteria. This nanorod based nanobiosensor can be an ideal candidate for optical detection and ablation of foodborne bacteria.