| Abstract
| - Antibody (human IgG, anti-E. coli O157:H7, and anti-Salmonella) complexes on the surface of IR-transparentGe-containing chalcogenide glass films were formed viathiol chemistry on 20-nm-thick gold islands. As a firststep, the protocol was validated by monitoring fluorescently tagged targets to validate binding. FT-IR spectroscopy confirmed that the coating of the films with 20-nmgold did not have a significant effect on the propagationand penetration of IR evanescent waves through the film.The films functionalized with anti-E. coli O157:H7 andanti-Salmonella antibodies were used to detect E. coliO157:H7 and S. enteriditis through label-free IR fingerprinting. Highly selective detection of bacterial targets wasachieved at both the species (E. coli vs. S. enteriditis)and strain level (E. coli O157:H7 vs E. coli K12). A mid-infrared approach could thus be used as a biosensor aswell as a molecular fingerprinting tool.
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