Research

Main scientific interest

Chemistry and photochemistry of porphyrinoids, singlet oxygen (O₂(¹Δ_g)), NO and I₂/I₃^– reactions/generation/detection, host-guest interaction, smart supramolecular systems, fotoactive polymer nanomaterials (nanofibers, nanoparticles, gels), applications in photodynamic inactivation (PDI) of bacteria, viruses and yeasts, application in photodynamic therapy (PDT).

Research equipment

Steady state as well as time-resolved absorption and emission spectroscopy, electrospinning device, standard equipment for synthesis and characterization of porphyrinoids.

Examples

Photofunctional nanofiber membranes

A novel photofunctional nanofiber materials (membranes) based on immobilization of the porphyrin photosensitizer in/on electrospun polymeric nanofibers. The nanofiber materials produce reactive singlet oxygen O₂(¹Δ_g) after irradiation by visible light causing that these materials have antibacterial and antiviral properties and can be used for photooxidation reactions and for oxygen sensing using singlet oxygen mediated delayed fluorescence (SODF).

Photo-antibacterial surfaces of nanofiber membranes

Escherichia coli  (Gram-negative)
Staphylococcus aureus  (Gram-positive)
Pseudomonas aeruginosa  (Gram-negative)
No bacterial resistance toward O₂(¹Δ_g) was found

Photodynamic inactivation (PDI) on the surface of the nanofiber membrane 1A toward bacteria E. coli  (green spots): Agar plates with pieces nanofiber membrane with a encapsulated photosensitizer (1) and a control nanofiber membranes without photosensitizer (2) inoculated with E. coli  and exposed to light (A) or kept in the dark (B)

Left picture:  Simultaneous generation of NO and O₂(¹Δ_g)
Right picture:  The amperometric detection of NO photoreleasing from the surface of nanofibers. The arrows indicate switch-on and switch-off character of NO releasing triggered by the irradiation by visible light.

Antibacterial, Antiviral & Oxygen Sensing Nanoparticles Prepared from Electrospun Materials

Supramolecular photosensitizers applied in photodynamic therapy (PDT)

Porphyrin-cyclodextrin host-guest interaction (example of supramolecular photosensitizer)

Cell line G361 human melanoma with porhyrin photosensitizer before (A) and after (B) the visible light irradiation. Example of photodynamic therapy (PDT).

Know-how & Technologies

• Synthesis and characterization of porphyrinoid photosensitizers
• Preparation of photoactive nanofiber materials by electrospinning generating O₂(¹Δ_g) and/or NO radicals
• Preparation of photoactive nanoparticles from nanofiber materials O₂(¹Δ_g) and/or NO radical
• Characterization of photoactive nanomaterials
• Detection methods for evaluation of (photo)generation of O₂(¹Δ_g) and/or NO radical in several media
• Antimicrobial photodynamic inactivation

Main capabilities

Controlled irradiation by several light sources (lasers, LED, lamps), steady state and time-resolved absorption and emission spectroscopy, synthesis of porphyrinoid photosensitizers, electrospinning, characterization of nanomaterials, chemical methods of O₂(¹Δ_g), other ROS, NO and I₂ detection, detection of oxygen in several media, photodynamic inactivation of bacteria.

Expectations & Offers

We offer our expertise within a several range of issues related to the design, preparation, and characterization/evaluation of photoactive supramolecular systems and/or nanomaterials with antimicrobial photodynamic inactivation.

Requirements

We are looking for highly motivated students and for cooperation especially in the fields of applications of photoactive nanomaterials in photocatalysis and medicine/biomedical science.