Microscopic VCD Scanning of Biological Organs

This chapter describes the prompt acquisition of two-dimensional VCD signals on a thin film. For this purpose, the system (named MultiD-VCD) using quantum cascade laser (QCL) is constructed. The spatial resolution is attained to a sub-millimeter scale. The system was applied to the hindwing of an insect as a biological sample. The organ consists of segregated microdomains (~100 μm in size) consisting of proteins with different secondary structures: i.e., veins (randomly coiled proteins), membranes (hybrids of α-helical and β-sheet proteins) and boundary areas (β-sheet proteins), respectively. Such structural characteristics are essential to the manifestation of multi-functionality by the organ.