Tip-enhanced Raman spectroscopy of cell wall heterogeneity for <i>Aspergillus Fumigatus</i>

Tip-enhanced Raman spectroscopy (TERS) enables nanoscale chemical mapping of biological structures beyond the capabilities of conventional Raman imaging. However, challenges such as the deformation of fragile biological cells would increase the difficulty in investigating biological samples with TERS. Here, we present strategies for utilizing TERS on cellular specimens and examine the cell wall heterogeneity of Aspergillus fumigatus spores. By employing TERS imaging and spectral analysis, we map the chemical components of the spore. Furthermore, by comparing the wild-type and albino mutant spores, we illuminate the characteristics of dihydroxynaphthalene melanin (DHN-melanin) in the fungal cell wall during TERS imaging.