3 years ago

Pt-Decorated MWCNTs–Ionic Liquid Composite-Based Hydrogen Peroxide Sensor To Study Microbial Metabolism Using Scanning Electrochemical Microscopy

Pt-Decorated MWCNTs–Ionic Liquid Composite-Based Hydrogen Peroxide Sensor To Study Microbial Metabolism Using Scanning Electrochemical Microscopy
Vrushali S. Joshi, Dipankar Koley, Jens Kreth
Hydrogen peroxide (H2O2) is a highly relevant metabolite in many biological processes, including the oral microbiome. To study this metabolite, we developed a 25 μm diameter, highly sensitive, nonenzymatic H2O2 sensor with a detection limit of 250 nM and a broad linear range of 250 nM to 7 mM. The sensor used the synergistic activity of the catalytically active Pt nanoparticles on a high surface area multiwalled carbon nanotube and conducting ionic liquid matrix to achieve high sensitivity (2.4 ± 0.24 mA cm–2 mM–1) for H2O2 oxidation. The unique composite allowed us to miniaturize the sensor and couple it with a Pt electrode (25 μm diameter each) for use as a dual scanning electrochemical microscopy probe. We could detect 65 ± 10 μM H2O2 produced by Streptococcus gordonii (Sg) in a simulated biofilm at 50 μm above its surface in the presence of 1 mM glucose and artificial saliva solution (pH 7.2 at 37 °C). Because of its high stability and low detection limit, the sensor showed a promising chemical image of H2O2 produced by Sg biofilms. We were also able to detect 30 μM H2O2 at 50 μm above the biofilm in the presence of the H2O2-decomposing salivary lactoperoxidase and thiocyanate, which would not otherwise be possible using an existing H2O2 assay. Thus, this sensor can potentially find applications in the study of other important biological processes in a complex matrix where circumstances demand a low detection limit in a compact space.

Publisher URL: http://dx.doi.org/10.1021/acs.analchem.7b01677

DOI: 10.1021/acs.analchem.7b01677

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.