Hinrichs, K.; Furchner, A.; Rappich, J.; Kratz, C.: Optofluidic analysis of monolayers with infrared microscopy. In: Reference Module in Chemistry, Molecular Sciences and Chemical EngineeringAmsterdam: Elsevier, 2023. - ISBN 978-0-1240-9547-2, p. 1-8
10.1016/B978-0-323-85669-0.00002-7
Abstract:
This contribution reviews analytical possibilities of IR spectroscopic in situ studies of nl liquid volumes using an optofluidic cell with a plasmonic enhancement surface in a microscopic reflection geometry. Four application fields are presented: (1) in situ IR microscopic analyses of the growth of self assembling monolayers, (2) chemical modification of a molecular interface, (3) functionalization of a graphene interface, and (4) streptavidin sensing by a biotinylated interface. Sub-monolayer sensitivity enables the detailed monitoring and characterization of molecular adsorption isotherms, covalent binding to a molecular interface, and operando molecular recognition of proteins. For the latter the vibrational amide I and amide II fingerprint gives information on the protein secondary structure and possible structural changes as a response to the binding process. Complementary Raman vibrational spectroscopic studies could be performed with the same or related optofluidic cell.