Biological characterization of antimicrobial and photocatalytic surfaces

At Fraunhofer IGB, we have developed standardized microbiological evaluation methods and adapted them to different questions in order to check the hygienic status of technical surfaces or to evaluate antimicrobial effective material surfaces.

Various test methods are available at Fraunhofer IGB, which are used depending on the question or are combined with one another. This includes established procedures for the examination of surfaces based on common test methods such as DIN-ISO or JIS. On the basis of microbiological, process engineering and / or molecular biological methods, test methods are also developed and established. This also includes the construction of technical test structures for application-oriented investigations.

Inactivation of microorganisms

In addition to the analysis of surfaces, we also develop and investigate methods for the inactivation of microorganisms on surfaces. Common methods for inactivating microorganisms are UV disinfection, ultrasonic disinfection and filtration of liquids.

At Fraunhofer IGB, scientists from the fields of interfacial process engineering and biology have been investigating alternative inactivation methods for microorganisms for years. For this purpose, investigations are based on common plasma and electrochemical processes for the inactivation of microorganisms on surfaces.

Fields of research

  • Quality assurance of cleaning and purification processes
  • Investigation of implant surfaces
  • Investigation of the antimicrobial properties of polymer surfaces

Test procedures

  • Light microscopic identification and documentation of microbial growth on surfaces
  • Identification of microorganisms on surfaces
  • Quantification of microbial growth on surfaces

Processes and equipment

  • Raman with 532 nm, 785 nm laser and CARS technology
  • Fluorescence microscopy (ZEISS Axio Observer Z1)
  • Sy-Lab BacTrac 4300 for quantification of bacteria
  • Quantitative real time PCR (qRT-PCR LightCycler 480)
  • Identification of microorganisms with DNA barcoding (bacteria according to 16S, fungi according to ITS)
  • Tecan Infinite 200 PRO
  • Screening processes
  • Investigations according to DIN EN ISO standards
  • Scanning electron microscopy (SEM)

Reference projects

Microbiological investigations into photocatalytic surfaces – a field trial

In order to investigate the exposure of polymer surfaces under practical conditions, a test facility was set up on the northwest side of the Fraunhofer IGB building as part of a joint project funded by the BMBF. Over a period of one year, various plastic surfaces that had been photocatalytically coated by project partners were examined and their effectiveness evaluated.

Photocatalytic coatings to counteract microorganisms on surfaces

The aim of the BMBF-funded joint project "Photokat" was to present practical, highly effective coatings with self-cleaning and self-disinfecting properties based on photocatalytically active titanium dioxide components for a variety of products with a wide range of applications. The microbiological evaluation of the various coatings was carried out at Fraunhofer IGB.