Masks off for science! Detecting viral material on face masks

The Corona pandemic still has us firmly in its grip despite the lifting of many government restrictions (e.g. face masks). Although we all hope that normality will soon return, epidemics and pandemics will likely become a part of our future lives.

In all of this, the use of face masks seemed to be a particularly sensitive topic. The value of face masks is undeniable when it comes to personal protection, but there might also be a „hidden value“.

Since face masks contain both environmental particles and respiratory aerosols they might be suitable for an early detection of infections. To test this hypothesis, Scientists at the University of Ulm (Schorer et al. 2022) tested a direct sampling method for disposable face masks.

Face masks – helpful in many ways

They used a combined approach of attenuated total reflection infrared spectroscopy (ATR) and data analysis with multivariate statistical algorithms.

Infrared spectroscopy is particularly well suited for this purpose. It is non-destructive, fast, and cost-effective. Furthermore, it is reliable and provides molecular information on a wide range of organic and inorganic substances.

First, the researchers sprayed facial masks with water, proteins (BSA), and virus-like particles (VLP). Second, after they let the masks dry, they were measured utilizing a Bruker ALPHA II with single-reflection ATR (Fig. 1).

Figure 1: Experimental Setup according to Schorer et al. 2022.

The combination of FT-IR and multivariate statistical algorithms allowed classifying spectral signatures of individual components. A specific model was created that demonstrated identification and differentiation (Fig. 2).

Figure 2: IR spectra collected with ALPHA II (left) and PLS model (right) by Schorer et al. 2022.

The model (Fig. 2) illustrates the clear distinction of both classes (BSA and VLP). Even minimal spectral differences enable virus detection and potentially discrimination. With their research, Schorer et al. 2022 might have added a new toolkit to virus detection.

What are the major advantages?

This new approach has important advantages over other methods.

  • no time-consuming sample preparation
  • no large amounts of waste
  • does not require trained personnel
  • … and most important: No annoying poking in nose and mouth

Schorer et al. 2022 mention several potential use cases of this new FT-IR approach, but especially the healthcare sector could be a key beneficiary.

Employees in hospitals and nursing homes are already working at the limit. During pandemics but also the normal respiratory disease season, this method might be a real relief.

While Bruker is in no way associated with the work of Schorer et al. 2022 we simply found the research approach very exciting. Thus we wanted to share it with our audience as the ALPHA II plays a key role in the article.

About the role of ALPHA II

For any kind of model creation the old addage applies: a model can only be as good as the data it is fed.

Naturally, researchers rarely talk about their FT-IR instrument’s spectral performance. And why would they? Our spectrometers are known for their high reliability and spectral precision anyway.

But in this case we want to highlight it, since principal component analysis and PLS models demand highest accuracy of raw data. In this context, the ALPHA II shines with excellent baseline stability and x-axis calibration (Fig. 3)

Figure 3: Comparison of ALPHA II baseline repeatability with a standard FT-IR spectrometer (transmission, 4 cm-1, 20 seconds measurement).

We are glad our instruments are part of this exciting and novel research and are curious to learn more about the suprising benefits of wearing a face mask. You’ve got other questions? Don’t hesitate and contact us through our website or take a look at our FTIR and Raman applications on this blog!References

Schorer, V., Haas, J., Stach, R. et al. Towards the direct detection of viral materials at the surface of protective face masks via infrared spectroscopy. Sci Rep 12, 2309 (2022).