Surface plasmon resonance-based bacterial aerosol detection

Abstract

Aims In the area of bioaerosol research, rapid methods for precise detection attracted much interest over last decades. One of such technologies operating in nearly real-time mode without any specific labelling is known as surface plasmon resonance (SPR). Recently, we validated a SPR protocol in conjunction with our earlier developed personal bioaerosol sampler for rapid detection of airborne viruses. Considering that the biological interaction between targeted micro-organism and corresponding antibody is strongly related to sizes of targeted micro-organisms, this research is vital validating suitability of SPR technique for bacterial aerosol detection, as characteristic size of bacteria is 2–3 orders of magnitude larger than sizes of common viruses. The combination of SPR with portable air sampling instrumentation could lead to the development of portable bioaerosol monitor.

Methods and Results This study is focussed on the SPR technology application for direct detection of common environmental bacterial strain—Escherichia coli. The detection limit of developed SPR techniques based on utilization of a planar gold sensor chip functionalized with polyclonal antibody via NeutrAvidin junction for sensing of bacterial cells was found to be 1·5 × 103 CFU ml−1, which corresponds to the limit of detection in the air to be 2·19 × 104 CFU l−1 for 1 min of sampling time.

Conclusions The technology was found fully suitable for rapid and reliable detection of large size bacterial aerosols. Low magnitude of the limit of detection looks very promising for sensitive detection of highly pathogenic airborne bacteria in the ambient air.

Significance and Impact of the Study The suggested technology based on a simple model organism is one of the first attempts to develop a real-time monitor for reliable detection of airborne bacteria. The outcomes would be of strong interest of professionals involved in monitoring and/or control of pathogenic airborne bacteria, including Legionella, Mycobacterium tuberculosis and Bacillus anthracis.