Microchimica Acta

, Volume 182, Issue 1–2, pp 385–394

Oxygen sensor nanoparticles for monitoring bacterial growth and characterization of dose–response functions in microfluidic screenings

  • Jialan Cao
  • Stefan Nagl
  • Erika Kothe
  • J. Michael Köhler
Original Paper

Abstract

We are presenting a microfluidic droplet-based system for non-invasive, simultaneous optical monitoring of oxygen during bacterial cultivation in nL-sized droplets using ~350 nm nanobeads made from polystyrene and doped with the NIR-emitting oxygen probe platinum (II) 5, 10, 15, 20-meso-tetraphenyltetrabenzoporphyrin (PtTPTBP). Data were readout by a two-channel micro flow-through fluorimeter and a two-channel micro flow-through photometer. The time-resolved miniaturized optical multi endpoint detection was applied to simultaneously sense dissolved oxygen, cellular autofluorescence, and cell density in nL-sized segments. Two bacterial strains were studied that are resistant to heavy metal ions, viz. Streptomyces acidiscabies E13 and Psychrobacillus psychrodurans UrPLO1. The study has two main features in that it demonstrates (a) the possibility to monitor the changes in oxygen partial pressure during metabolic activity of different bacterial cultures inside droplets, and (b) the efficiency of droplet-based microfluidic techniques along with multi-parameter optical sensing for highly resolved microtoxicological screenings in aquatic systems.

Graphical Abstract

Microfluidic droplet-based system with multi-parameter optical sensing for bacterial cultivation and highly resolved microtoxicological screenings in nanoliter droplets.

Keywords

Droplet-based microfluidics Oxygen sensor Optical probe-doped micro and nanoparticles Micro cultivation Highly-resolved dose/response function 

Copyright information

© Springer-Verlag Wien 2014

Authors and Affiliations

  • Jialan Cao
    • 1
  • Stefan Nagl
    • 2
  • Erika Kothe
    • 3
  • J. Michael Köhler
    • 1
  1. 1.Institute of Micro- and Nanotechnologies/Institute for Chemistry and Biotechnology, Department of Physical Chemistry and Microreaction TechnologyIlmenau University of TechnologyIlmenauGermany
  2. 2.Institute of Analytical ChemistryUniversity of LeipzigLeipzigGermany
  3. 3.Institute of Microbiology, Department of Microbial CommunicationFriedrich-Schiller-UniversityJenaGermany

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