Detection of Amines on Surfaces using Two-Photon-Fluorescence Microscopy

Metrology in Life Sciences

My research field contains laser systems and fluorescence microscopy. The main aspect of my work is the detection of amines on surfaces, for example membranes, nanoparticles or polymers. This can be done with two-photon fluorescence microscopy by measuring the fluorescence intensity or fluorescence lifetime of a fluorophore which is specific for amines and labeled on the surface of the substrate. Reacting primary and secondary amino groups with fluorescent labels allows 3D intensity distribution measurements with sub-micron resolution. Two-photon microscopy is especially suited for porous substrates with high sampling depths. With help of fluorescence lifetime measurements by ps-resolved fluorescence recording and suitable references absolute amino group concentrations, respectively densities are accessible which allow comparison with other analysis methods. Fluorescence anisotropy measurements enable insight into the molecular rotation of fluorescent labels and hence about the substrate matrix environment. Altogether, fluorescence analysis provides valuable information about the substrate surface topography, amino group density and uniformity as well as the binding situation with the substrate. Especially the binding situation of the amines to their substrate can be very important for the respective fields of application. Some applications are amino groups on plasma functionalized polymers used as anchor groups in combinatorial synthesis for bioassays or microarrays, amines stabilizing nanoparticles or amines on membranes used for dialysis.

TU Braunschweig
in progress
Ph.D. student: