Research Focus: Biophotonics | Life Sciences | Environmental Analytics

Cytochrome-c - a protein to see into bacteria.
Raman spectrum of a Nitrosomonas bacterium.

As part of its applied research in optical technologies, the HOT works on several focal topics from the fields of biophotonics, life sciences, and environmental analytics.

Currently, our work focuses on 

  • microplastics: online-detection in flowing drinking water
  • microalgae: carotenoid analysis and effects of environmental stress
  • bacteria: non-invasive analysis of relative relatedness („in vivo phylogeny“)
  • biofilms: non-invasive observation over time, species identification, and 3D structure
  • human skin: optical analytics (dermatoscopy, melanoma thickness, quantification of carotenoids, vitamin D synthesis)
  • inner ear: non-invasive optical diagnostics
  • proteins: functional analysis

Experimental Methods and Data Analysis

For this, we are working on new or improved experimental and data analysis methods:

  • Multivariate and cluster analysis: for the discrimination and grouping of spectra
  • Raman Resonance Profiles: high-resolution resonance profiles, molecular identfication, and tunable Rayleigh-filters
  • Simulation and image processing: Raman spectra, OCT, opto acoustics, photophysics and -chemistry

Optical Methods

Our most often used optical methods are

  • confocal Raman microscopy (spatial resolution at cell level; molecular information)
  • resonance Raman spectroscopy (molecular and molecular group-information)
  • absorption- and transmission spectroscopy
  • holographic microscopy
  • opto acoustics
  • optical coherent tomography (OCT)

and the combination of these methods.


  • RRS-OA
    Leaders: M. Wollweber
    Year: 2011
    Sponsors: DFG
  • OCT
    Leaders: B. Roth, M. Rahlves
    Year: 2011
    Year: 2011
  • Research Initiative "Water and Security"
    Leaders: B. Roth, M. Wollweber
    Team: A.-K. Kniggendorf
    Year: 2011
  • Hautkrebsscreening (HKS)
    Entwicklung eines digitalen Dermatoskopiegerätes mit erweitertem Diagnoseumfang für das automatisierte Ganzkörper-Hautkrebs-Screening (Melanom-früherkennung)
    Leaders: M. Wollweber
    Year: 2012
  • Determination of melanoma thickness via optoacoustics and optical coherence tomography (OCT)
    Development of a method for the preoperative determination of the thickness of melanoma suspicious skin lesions.
    Leaders: B. Roth, M. Wollweber, U. Morgner, M. Rahlves
    Year: 2013
    Sponsors: BMBF
  • OPTIMUS -Raman spectroscopy of microplastics, microbes, and trace elements
    online detection of contaminated microplastics in streaming drinking water with Raman spectroscopy for the BMBF joint project OPTIMUS.
    Leaders: B. Roth
    Team: A.-K. Kniggendorf
    Year: 2016
    Sponsors: Bundesministerium für Bildung und Forschung (BMBF)
  • Smartphone based optical point of care tests
    Leaders: K. Bremer, B. Roth
    Team: M. Rahlves
    Year: 2017
    Sponsors: Bundesministerium für Wirtschaft und Energie (BMWi) und Europäischer Sozialfond (ESF)
  • AMIRA - Analysis of microbial relations in vivo using Raman microscopy
    Projekt AMIRA is a cooperation between HOT and the department for Hydrobiology and Environmental Biotechnology at the Institute for Sanitary Engineering and Waste Management (ISAH) of the LUH and intends to establish cytochrome c-resonant Raman microscopy (CRRM) for the continuous analysis of bacterial relations in native, undisturbed biofilms in vivo and in situ with a resolution at cell level. This will allow for the time the direct observation of ongoing biofilm formation including phylogenetic information and phenotypic adaptation in complex biofilms in vivo.
    Leaders: A.-K. Kniggendorf
    Year: 2018
    Sponsors: Deutsche Forschungsgemeinschaft (DFG) - 397827619