A field-deployable immunofluorescence chip for adenovirus monitoring in groundwater systems

Rapid field detection of human adenoviruses in groundwater remains a critical technological gap, particularly for riverbank filtration systems, exposed to extreme weather and contamination events. Here, we present the VIRUMEX chip, a field-deployable platform that captures and detects adenovirus proteins through popular immunofluorescence mechanism using antibody-functionalized 3D Sepharose beads integrated into a disposable flow-through microfluidic cartridge. Powered by a compact peristaltic pump, the system autonomously processes groundwater and yields fluorescence-based readouts in light intensity unit (LIU) within 4-8 h, enabling near-real time semi-quantitative pathogen surveillance. Laboratory tests produced a clear detectable signal at 0.129 ng/mL (1000 LIU) for adenovirus hexon protein, and field deployment in the Erpe River catchment produced above-background fluorescence (800 LIU) in river water, providing proof-of-concept evidence with positive signal under real riverbank filtration conditions, while groundwater samples remained negative under the tested conditions. By providing an on-site, rapid, and operationally simple detection method, the VIRUMEX chip provides an additional on-site virus screening prototype alongside qPCR and isothermal approaches and offers a promising prototype for integrating virus monitoring into groundwater safety frameworks which needs some further optimizations before it can be regarded as a fully validated detection tool.