Nanotechnology for Foodborne Pathogenic Bacteria Detection - Bosoon Park
From Katie Gentilello
Among several potentials of nanotechnology applications in food, development of nanoscale sensors for food safety and security measurement are emerging. A novel bio-functional nanosensor for foodborne pathogenic bacteria detection was developed using hetero-Au/Si nanorods. For the development of nanobiosensor, the protocol for bio-functional nanorod fabrication has been developed. The protocols include; 1) Silicon nanorod fabrication including substrate preparation and deposition control; 2) Surface oxidation including annealing and oxygen plasma process; 3) Nanoparticle coating onto the silicon using sputter coating system; 4) Biological dye immobilization including APTES treatment and incubation process; 5) Antibody conjugation with DSP pretreatment and antibody incubation followed by antigen/infected cells preparation; finally, 6) Antigen/infected cells detection by bio-functional nanorods. The Si nanorods were fabricated by glancing angle deposition (GLAD) method, and Au was sputtered onto the silicon nanorods. Alexa488-succinimide dye molecules were immobilized onto the annealed silicon nanorods thru the attachment between dye ester and primary amine supplied by 3-Aminopropyltriethoxysilane (APTES). Anti-Salmonella was conjugated to the Au via Dithiobis [succinimidylpropionate] (DSP) self-assembly monolayer (SAM). Due to the high aspect ratio nature of Si nanorods, hundreds or thousands of dye molecules attached to silicon nanorods enhanced fluorescence signals. These biologically functionalized nanorods can be used for nanobiosensor to detect foodborne pathogenic bacteria with fluorescent microscopic imaging. This new nanoscale sensing technology will be of great significance for food safety and security applications as well as biomedical diagnostics.