Sniffing Bacteria with a Carbon-Dot Artificial Nose

Nitzan Shauloff, Ahiud Morag, Karin Yaniv, Seema Singh, Ravit Malishev, Ofra Paz-Tal, Lior Rokach, Raz Jelinek

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


Highlights: Novel artificial nose based upon electrode-deposited carbon dots (C-dots). Significant selectivity and sensitivity determined by “polarity matching” between the C-dots and gas molecules.The C-dot artificial nose facilitates, for the first time, real-time, continuous monitoring of bacterial proliferation and discrimination among bacterial species, both between Gram-positive and Gram-negative bacteria and between specific strains.Machine learning algorithm furnishes excellent predictability both in the case of individual gases and for complex gas mixtures. Abstract: Continuous, real-time monitoring and identification of bacteria through detection of microbially emitted volatile molecules are highly sought albeit elusive goals. We introduce an artificial nose for sensing and distinguishing vapor molecules, based upon recording the capacitance of interdigitated electrodes (IDEs) coated with carbon dots (C-dots) exhibiting different polarities. Exposure of the C-dot-IDEs to volatile molecules induced rapid capacitance changes that were intimately dependent upon the polarities of both gas molecules and the electrode-deposited C-dots. We deciphered the mechanism of capacitance transformations, specifically substitution of electrode-adsorbed water by gas molecules, with concomitant changes in capacitance related to both the polarity and dielectric constants of the vapor molecules tested. The C-dot-IDE gas sensor exhibited excellent selectivity, aided by application of machine learning algorithms. The capacitive C-dot-IDE sensor was employed to continuously monitor microbial proliferation, discriminating among bacteria through detection of distinctive “volatile compound fingerprint” for each bacterial species. The C-dot-IDE platform is robust, reusable, readily assembled from inexpensive building blocks and constitutes a versatile and powerful vehicle for gas sensing in general, bacterial monitoring in particular.[Figure not available: see fulltext.]

Original languageEnglish
Article number112
JournalNano-Micro Letters
Issue number1
StatePublished - 20 Apr 2021


  • Bacterial detection
  • Bacterially emitted volatile molecules
  • Capacitive gas sensors
  • Carbon dots
  • Gas polarity

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Surfaces, Coatings and Films
  • Electrical and Electronic Engineering


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