Tapping-mode scanning probe electrospray ionization: fusion of SPM with mass spectrometry

Biological tissues are composed of a wide variety of chemical components, in which the amount and distribution of these components change dynamically according to health status. Mass spectrometry imaging (MSI) can be applied to biomedical research because of its ability to measure chemical components in a sample’s local area as a mass spectrum and visualize the chemical species distribution in a sample. This study reviewed the development of the tapping-mode scanning probe electrospray ionization (t-SPESI) technique to combine atomic force microscopy and mass spectrometry. t-SPESI uses a vibrating capillary probe to achieve rapid extraction, ionization, and MSI using picoliter solvents. Visualizing the distribution of disease-related components in the tissue was performed in the MSI of biological tissue. Multimodal imaging by t-SPESI was also demonstrated by implementing the optical detection of a probe vibration and the feedback control system into the t-SPESI.