Nanomaterial Reactivity for Clean Air: From Operando Heterogeneous Catalysis to Airborne Pathogen Inactivation

Respiratory tract infections are the third leading cause of death worldwide, with airborne transmission as their primary propagation route. Virus-containing aerosols can remain suspended in air and retain infectivity for hours.

Operando Raman studies demonstrate the key role of reactive oxygen species (ROS) in enabling efficient VOC combustion at low temperatures. This expertise in combustion catalysis is highly relevant to airborne pathogen inactivation strategies.

Through the H2020 NanoInformaTIX project, focused on the reactive bases of nanoparticle toxicity, we developed predictive frameworks for the environmental health and safety of nanomaterials by elucidating how nanomaterial reactivity governs cell viability. In this context, acellular oxidative stress assays were established to correlate surface reactivity with adverse outcomes, classifying nanomaterials into three categories: inert materials with negligible cytotoxicity; highly reactive materials inducing cell death; and intermediately reactive materials that cause sublethal damage and trigger autophagic responses.

Building on this oxidative damage paradigm, through the LaCaixa SafeAir project, we extend this knowledge to the remediation of airborne viruses and bacteria using catalytic filters. Our acellular assays, based on probe organic reactions, have been adapted to quantify the oxidative potential of catalytic systems and benchmarked against viral inactivation determined by plaque assays. These studies include human coronavirus 229E (HCoV-229E) and SARS-CoV-2, and rhinovirus 14 (RV-14).

ACKNOWLEDGEMENTS. We gratefully acknowledge the funding from European Union’s Horizon 2020 research and innovation programme under grant agreement No 814426 (NanoInformaTIX), CSIC PTI+ Salud Global, NextGenerationEU (Regulation EU 2020/2094), by “la Caixa” Bank Foundation, LCF/PR/HR22/52420032 and COST Action CA23139 Net4CleanAir.