1. Drug Research Program, Division of Pharmaceutical Biosciences, Centre for Drug Research, University of Helsinki, Helsinki, Finland;2. Chair of Bioprocess Engineering, Institute of Biotechnology, Technische Universit?t Berlin, Berlin, Germany;3. Aix‐Marseille Univ, CNRS, Marseille, France;4. P.N. Lebedev Physical Institute of Russian Academy of Sciences, Moscow, Russia;5. VTT – Technical Research Centre of Finland, Oulu, Finland;6. Optoelectronics and Measurement Techniques, Faculty of Information Technology and Electrical Engineering, University of Oulu, Oulu, Finland;7. ITMO University, St. Petersburg, Russia;8. National Resources Institute Finland (LUKE), Bio‐based Business and Industry, University of Oulu, Oulu, Finland;9. Natural Research Institute Finland (LUKE), Bio‐based Business and Industry, Turku, Finland;10. National Research Nuclear University “MEPhI”, Institute of Engineering Physics for Biomedicine (PhysBio), Moscow, Russia
Abstract:
The ability of noble metal‐based nanoparticles (NPs) (Au, Ag) to drastically enhance Raman scattering from molecules placed near metal surface, termed as surface‐enhanced Raman scattering (SERS), is widely used for identification of trace amounts of biological materials in biomedical, food safety and security applications. However, conventional NPs synthesized by colloidal chemistry are typically contaminated by nonbiocompatible by‐products (surfactants, anions), which can have negative impacts on many live objects under examination (cells, bacteria) and thus decrease the precision of bioidentification. In this article, we explore novel ultrapure laser‐synthesized Au‐based nanomaterials, including Au NPs and AuSi hybrid nanostructures, as mobile SERS probes in tasks of bacteria detection. We show that these Au‐based nanomaterials can efficiently enhance Raman signals from model R6G molecules, while the enhancement factor depends on the content of Au in NP composition. Profiting from the observed enhancement and purity of laser‐synthesized nanomaterials, we demonstrate successful identification of 2 types of bacteria (Listeria innocua and Escherichia coli). The obtained results promise less disturbing studies of biological systems based on good biocompatibility of contamination‐free laser‐synthesized nanomaterials.
