2024 Volume 9 Issue 1 Pages 13-20
We present our recent works on vibrational circular dichroism spectroscopy (VCD). VCD is a chiro-optical method detecting molecular chirality in the infrared region. A main attention has been focused on the asymmetric structures (called “supramolecular chirality”) that appear when many molecules are linked together, such as seen in gels and molecular crystals. Recently, we have developed a multi-dimensional infrared circular dichroism spectroscopy (named the multi-dimensional VCD method) with a microscopic function by adding time and space axes to the conventional wavenumber axis. Spatial resolution of 100 μm was achieved by using a quantum cascade laser as a highly brilliant infrared light source. Here, we describe the application of the solid-state VCD method to amino acids and peptides. Next, we introduce the application of the microscopy technique to insect wings as an example of biological samples. It is revealed that a wing comprises the heterogenous distribution of protein domains in various secondary structures.
