Laser scanning confocal microscopy is a modern technique that provides the opportunity for three-dimensional, high-resolution, non-destructive imaging of a whole range of samples from biological cells to semiconductor devices. Our laboratories are equipped with several commercial and self-built setups tailored for different applications. In addition to the conventional LSCM we are developing also more advanced method such as two photon laser scanning microscopy, second harmonic generation microscopy, fluorescence life time imaging, etc.
Currently we are working on several research projects in which LSCM is a major tool:

Imaging of colloidal systems
We use confocal microscopy to determine the structure of colloidal systems and to follow up their dynamics. This gives us access to the motion of single colloids within the structure. These observations we can use to test the stability of a structure to perturbations such as external fields, or to study propagation and dynamics of defects.

See also: Mechanical Properties of Colloidal Aggregates

Solid-supported thin elastomer films deformed by microdrops
We use LSCM to obtain 3D images of an ionic liquid microdrop stained with fluorescent die (red) staying on a soft PDMS surface (green). The cross-section of these 3D images show directly how the droplet deforms the soft surface.

See also: Drops on Soft Surfaces

Phase separation in polymer blends
We use LSCM to study in-situ the phase separation in polymer blends. The images show 50:50 blend of PMPS and fluorescently labeled PS with molecular weights of 2k and 12k respectively, annealed for different times at a temperature of 100°C.

Direct visualization of the inversed domain structure in NLPC
Using the strong enhancement of the Cherenkov type second harmonic generation on the boundary between two anti-parallel domains in ferroelectric crystals we have developed a new method for fast, un-destructive 3D visualization of the inversed domain structure in nonlinear photonic crystals based on laser scanning second harmonic generation microscopy.

See also: Nonlinear Photonic Crystals

Self assembled fluorescent vesicles
In cooperation with Dr. Franziska Gröhn , we have studied vesicles consisting of cationic G8 poly(amidoamine) dendrimers and the trivalent sulfonate dye Ar27, formed due to the interplay of electrostatics and π-π interactions. Fluorescent guest molecules, e.g. small chromophores or labeled peptides, can be included inside these vesicles and the vesicles can be imaged by confocal laser scanning microscopy.

Fluorescent micelles uptake in living cells
In cooperation with Dr. Tanja Weil we study the receptor-mediated uptake of polypeptide copolymer micelles loaded with highly lipophilic chromophores in living cells. The image above shows receptor-mediated endocytotic uptake in KB cells of tetraphenoxyperylenediimide (PDI) dye entrapped in micelles bearing folic acid residues.

Local enhancement of two photon induced fluorescence trough the evanescent field of metal nanoparticles
In cooperation with Dr. Max Kreiter we study the local enhancement of two-photon induced fluorescence or photo-cleavage trough the evanescent field of metal nanoparticles. The images above show the fluorescence of an Alexa 488 layer covering crescent shaped gold nanoparticles (resonance around 800 nm) deposited on a glass slide upon one-photon (a) and two-photon (b) excitation. The scale bar represents 5 μm.