Unravelling Nanoscale Chemistries in Complex Biological Systems Using Photoinduced Force Microscopy

The attached datasets are the raw PiFM data files. They can be analysed by Molecular Vista's Surface works software. Contact Mol Vista at: https://molecularvista.com/<b>Abstract</b><br>Biological systems, whether mammalian cells, bacterial colonies, or their secretory pathways, are intrinsically heterogeneous, hierarchically organised, and chemically complex. These systems function through interdependent processes spanning multiple length scales, where nanoscale organisation informs and drives microscale biological behaviour. To interrogate these structurally and chemically diverse systems in their native state, particularly at the interface of molecular specificity and spatial resolution, requires correlative, label-free techniques capable of spanning these scales. Here, we demonstrate the utility of <b>Photoinduced Force Microscopy (PiFM)</b> as a powerful nano-vibrational spectroscopy imaging technique to probe the physicochemical landscape of biological systems across length scales, from sub-10 nm chemical mapping to entire cells. PiFM combines the spatial resolution of atomic force microscopy with the molecular specificity of infrared spectroscopy, enabling both point spectra acquisition and hyperspectral chemical imaging with resolution down to ~5 nm. Importantly, its adjustable sampling depth (∼20 and ~200 nm) allows interrogation of surface and subsurface features without the need for extensive sample preparation.