Nanostructured diamond layers enhance infrared spectroscopy of biomolecules

Optical gold elements coated with diamond layers with flat, nanocolumnar, and nanoporous morphologies. Fabricated diamond coated optical elements were successfully used for the grazing angle reflectance FTIR characterization of fetal bovin serum (FBS) proteins adsorbed on the O-terminated diamond surface. In spite of the different processing and structuring, all types of diamond layers showed good stability, uniformity, and optical properties, including good reflectivity of the gold mirrors.

Schematic drawings and SEM images of diamond layers with flat (a), nanocolumnar (b), and nanoporous (c) morphologies deponed on commercial optical AU mirrors. Comparison of GAR-FTIR intensities C=O (d) and CN/NH (e) functional groups from FBS proteins of 3 and 10 nm widths adsorbed on diamond layers with different surface morphology.

¹Institute of Physics of the ASCR, v.v.i., Prague, Czech Republic