Microscopic and Spectroscopic Characterization of Nanostructured Topographical Surface of Rattlesnake Rattle

Rattlesnakes are easily recognized by a rattle on the tail. Despite the advances in molecular, morphological, and evolutionary studies about several aspects of rattles, there are no studies elucidating these nanoscale topographical features using high-resolution techniques. Here we propose a set of approaches to show these micro/nano surface features searching for patterns or hidden signatures. The results showed that the older rattle ring (segment 8) presented higher roughness values when compared to other segments. Cluster analysis allowed the observation of similarities/differences among some groups, which reinforced the strong discrepancy of the segment 8 when compared to the others and enable possible topographical transitions among each segment features, considering their linkages and Euclidean distances. Attractive forces and surface hardness were also significant increased on segment 8, while adhesion was significantly decreased on the segments 5, 6, and 7 compared to segment 1 (P < 0.05). Fourier transform infrared spectroscopy showed typical profiles of keratin spectra considering the amino acids present in this protein structure. Energy dispersive spectroscopy results indicated possible different molecular composition on each segment. These set of approaches applied on the present study represents an array of new possibilities towards the qualitative and quantitative analyses of this type of biomaterials enabling to address several structural, chemical and mechanical questions ongoing on scientific world.