(651a) Flame-Made Nanoparticles for Molecular Sensing

Combustion aerosol technology has distinct advantages for the assembly of molecular sensors (e.g. chemoresistive or plasmonic) compared to their traditional wet chemistry synthesis. These advantages are traced to combustion’s steep temperature gradients and high particle concentrations during sensing particle formation and film deposition. This gives direct access to a plethora of material compositions (e.g. metastable phases, solid solutions, mixed oxides) and fractal-like porous but rigid structures that can lead to unique sensor selectivity, sensitivity and stability along with short response and recovery times.[1] Here, I will discuss our recent advances on the nanoscale engineering of flame-made molecular sensing materials and filters. For instance, finely dispersed CuO_x clusters on Co₃O₄ will be presented that enable the selective detection of formaldehyde at low operational temperatures.[2] This will be followed by the design of highly reactive noble-metal clusters for plasmonic gas sensing that enable selective air pollutant detection with wearables even by naked eye.[3] I will show how metastable crystal phases are captured that enable unprecedented humidity robustness and selective benzene sensing, even over chemically similar molecules. Finally, devices for food quality assessment[4]and safe green fuels handling will be discussed that have been commercialized recently and sold to customers in 26 countries on 5 continents[5], demonstrating the immediate practical impact of such flame-made sensors.

[1] Güntner, A. T., Pineau, N. J. & Pratsinis, S. E. Prog. Energy Combust. Sci. 90, 100992, doi:https://doi.org/10.1016/j.pecs.2022.100992 (2022).
[2] D'Andria, M., Krumeich, F., Yao, Z., Wang, F. R. & Güntner, A. T. Adv. Sci., 2308224, doi:https://doi.org/10.1002/advs.202308224 (2024).
[3] Güntner, A. T. & Schenk, F. M. Nanoscale 15, 3967-3977, doi:10.1039/D2NR06599A (2023).
[4] Abegg, S., Magro, L., van den Broek, J., Pratsinis, S. E. & Güntner, A. T. Nature Food 1, 351-354, doi:https://doi.org/10.1038/s43016-020-0095-9 (2020).
[5] Güntner, A. T., D’Andria, M. & van den Broek, J. Nature Reviews Bioengineering 1, 385-387, doi:10.1038/s44222-023-00068-y (2023).