Related Experiment Video
Updated: Jun 9, 2026
07:09
Use of a High-throughput In Vitro Microfluidic System to Develop Oral Multi-species Biofilms
Published on: December 1, 2014
13.9K
A Minimally Invasive Microsensor Specially Designed for Simultaneous Dissolved Oxygen and pH Biofilm Profiling
Xavier Guimerà1, Ana Moya2,3, Antonio David Dorado4
1Department of Mining Industrial and ICT Engineering, Universitat Politècnica de Catalunya, Avinguda de les Bases de Manresa 61-73, 08242 Manresa, Spain. xavier.guimera@emrn.upc.edu.
Sensors (Basel, Switzerland)
|November 6, 2019
Summary
A novel microsensor simultaneously measures dissolved oxygen and pH in biofilms, offering improved tools for biological system characterization. This minimally invasive device enhances biofilm monitoring and activity assessment.
Area of Science:
- Bioanalytical Chemistry
- Microscale Sensing Technology
- Microbial Ecology
Background:
- Accurate in-situ monitoring of dissolved oxygen (DO) and pH is crucial for understanding biofilm physiology and function.
- Existing methods often lack the spatial resolution or minimally invasive nature required for detailed biofilm profiling.
- Advanced sensing technologies are needed to capture dynamic microenvironmental gradients within biofilms.
Purpose of the Study:
- To develop and validate a novel microsensor for simultaneous, in-situ dissolved oxygen (DO) and pH monitoring within biofilms.
- To improve the characterization of biological systems by providing instantaneous dynamic profiles.
- To enable the quantification of mass transfer resistances and assessment of biological activity in biofilms.
Main Methods:
- Fabrication of a dual-electrode microsensor on a flexible polyimide substrate.
- Utilizing gold microelectrodes for DO sensing and iridium oxide-modified platinum microelectrodes for pH sensing.
- Employing a Nafion® coating for enhanced sensor stability, repeatability, and fouling resistance.
- Validation in a flat plate bioreactor for profiling a sulfide-oxidizing biofilm.
Main Results:
- The microsensor achieved simultaneous, instantaneous DO and pH profiling within biofilms.
- DO microelectrodes exhibited a linear response (0-8 mg L⁻¹) with a detection limit of 0.05 mg L⁻¹.
- pH electrodes demonstrated a linear super-Nernstian response (74.2 ± 0.7 mV/pH unit) across a pH range of 4-9.
- Minimally invasive design and high spatial resolution improved biofilm monitoring performance.
Conclusions:
- The developed microsensor offers a significant advancement in biofilm monitoring tools.
- It enables detailed in-situ characterization of microenvironmental conditions and biological activity.
- This technology facilitates the quantification of mass transfer limitations and enhances the study of complex biological systems.
