Carbon Dots Detect Water-to-Ice Phase Transition and Act as Alcohol Sensors via Fluorescence Turn-Off/On Mechanism

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

6 Scopus Citations
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Author(s)

  • Sergii Kalytchuk
  • Lukáš Zdražil
  • Zdeněk Bad'ura
  • Miroslav Medved'
  • Michal Langer
  • Markéta Paloncýová
  • Giorgio Zoppellaro
  • Stephen V. Kershaw
  • Michal Otyepka
  • Radek Zbořil

Detail(s)

Original languageEnglish
Pages (from-to)6582–6593
Journal / PublicationACS Nano
Volume15
Issue number4
Online published16 Mar 2021
Publication statusPublished - 27 Apr 2021

Abstract

Highly fluorescent carbon nanoparticles called carbon dots (CDs) have been the focus of intense research due to their simple chemical synthesis, nontoxic nature, and broad application potential including optoelectronics, photocatalysis, biomedicine, and energy-related technologies. Although a detailed elucidation of the mechanism of their photoluminescence (PL) remains an unmet challenge, the CDs exhibit robust, reproducible, and environment-sensitive PL signals, enabling us to monitor selected chemical phenomena including phase transitions or detection of ultralow concentrations of molecular species in solution. Herein, we report the PL turn-off/on behavior of aqueous CDs allowing the reversible monitoring of the water-ice phase transition. The bright PL attributable to molecular fluorophores present on the CD surface was quenched by changing the liquid aqueous environment to solid phase (ice). Based on light-induced electron paramagnetic resonance (LEPR) measurements and density functional theory (DFT) calculations, the proposed kinetic model assuming the presence of charge-separated trap states rationalized the observed sensitivity of PL lifetimes to the environment. Importantly, the PL quenching induced by freezing could be suppressed by adding a small amount of alcohols. This was attributed to a high tendency of alcohol to increase its concentration at the CD/solvent interface, as revealed by all-atom molecular dynamics simulations. Based on this behavior, a fluorescence "turn-on"alcohol sensor for exhaled breath condensate (EBC) analysis has been developed. This provided an easy method to detect alcohols among other common interferents in EBC with a low detection limit (100 ppm), which has a potential to become an inexpensive and noninvasive clinically useful diagnostic tool for early stage lung cancer screening.

Research Area(s)

  • alcohol nanosensors, carbon dots, diagnostics, phase transition, photoluminescence

Citation Format(s)

Carbon Dots Detect Water-to-Ice Phase Transition and Act as Alcohol Sensors via Fluorescence Turn-Off/On Mechanism. / Kalytchuk, Sergii; Zdražil, Lukáš; Bad'ura, Zdeněk; Medved', Miroslav; Langer, Michal; Paloncýová, Markéta; Zoppellaro, Giorgio; Kershaw, Stephen V.; Rogach, Andrey L.; Otyepka, Michal; Zbořil, Radek.

In: ACS Nano, Vol. 15, No. 4, 27.04.2021, p. 6582–6593.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review