Fraunhofer Institute for Microengineering and Microsystems IMMDissertation Dongzhe He
Microfluidic Systems for On-Site Detection of Microorganisms
We congratulate Dongzhe He on the successful defense of his doctoral theses in the field of microfluidic systems. In his work, Dongzhe He focuses on the on-site detection of microorganisms and the development of a multifunctional bioanalytical cartridge.
Dongzhe He is a research scientist in the “Bioanalytics in Industrial Media” group of the Division Bioanalytics & Diagnostics at Fraunhofer IMM. The defense of his dissertation on “Microfluidic Systems for On-Site Detection of Microorganisms” took place on June, 16 2026, at Johannes Gutenberg-Universität Mainz, Germany.
We wish Dongzhe He every success in his future career and personal life.
Abstract
Conventional detection procedures for waterborne pathogens are manual and time-consuming. A long analysis duration could miss the best reaction time to prevent infectious disease outbreaks. This study aims to automate the manual detection procedures for waterborne pathogens using microfluidic technologies.
This work consists of optimising a sample concentration module established by Fraunhofer IMM and developing a multifunctional bioanalytical cartridge. Both systems are evaluated using Legionella bacteria, which are commonly detected in artificial water systems.
The optimized concentration module enables large-volume sample concentration (e.g., 1 L) down to 100–200 μL within 10 minutes fully automatedly. The recovery efficiency for Legionella is nearly 100% at concentrations exceeding 10⁴ CFU/L but drops significantly and becomes inconsistent at lower levels.
The multifunctional bioanalytical cartridge is developed based upon a quantitative polymerase-chain-reaction (qPCR) cartridge developed at Fraunhofer IMM. The PCR cartridge is integrated with cell lysis, reaction volume extraction, pre-loaded PCR re-agents, homogenisation of the PCR mixture followed by qPCR.
The cartridge is innovative because it is fully automated and requires few reagents and materials. The functionality of the cartridge has been proved, while the qPCR performance for Legionella is currently restricted by suboptimal PCR reagents. The multifunctional cartridge can be paired with the sample concentration module to fully automate the detection procedure.