Colloidal cold filtrates as metal substrates for surface-enhanced infrared absorption spectroscopy

摘要

A new method for obtaining surface-enhanced infrared absorption (SEIRA) spectra of antibodies and antibody/antigen complexes has been developed. Antibodies attached to colloidal gold particles and then collected by filtration onto porous polyethylene membranes show enhanced spectral bands at 1080 and 990 cm(-1) regardless of the antibody specificity. Attachment of a model antigen, glucose oxidase, to its specific antibody/colloid complex prior to collection produces enhanced bands at 1540, 1395, and 1250 cm(-1). Similarly, when the antigen Salmonella is attached to its specific antibody/colloid complex prior to collection, a new enhanced band is observed at 1015 cm(-1). Similarities and differences of the SEIRA spectra obtained on gold colloid are compared to previous work on gold films. [References: 16]