Single-Particle Ratiometric Pressure Sensing Based on "double-Sensor" Colloidal Nanocrystals

Monica Lorenzon, Valerio Pinchetti, Francesco Bruni, Wan Ki Bae, Francesco Meinardi, Victor I. Klimov, Sergio Brovelli

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)


Ratiometric pressure sensitive paints (r-PSPs) are all-optical probes for monitoring oxygen flows in the vicinity of complex or miniaturized surfaces. They typically consist of a porous binder embedding mixtures of a reference and a sensor chromophore exhibiting oxygen-insensitive and oxygen-responsive luminescence, respectively. Here, we demonstrate the first example of an r-PSP based on a single two-color emitter that removes limitations of r-PSPs based on chromophore mixtures such as different temperature dependencies of the two chromophores, cross-readout between the reference and sensor signals and phase segregation. In our approach, we utilize a novel "double-sensor" r-PSP that features two spectrally separated emission bands with opposite responses to the O2 pressure, which boosts the sensitivity with respect to traditional reference-sensor pairs. Specifically, we use two-color-emitting dot-in-bulk CdSe/CdS core/shell nanocrystals, exhibiting red and green emission bands from their core and shell states, whose intensities are respectively enhanced and quenched in response to the increased oxygen partial pressure that effectively tunes the position of the nanocrystal's Fermi energy. This leads to a strong and reversible ratiometric response at the single particle level and an over 100% enhancement in the pressure sensitivity. Our proof-of-concept r-PSPs further exhibit suppressed cross-readout thanks to zero spectral overlap between the core and shell luminescence bands and a temperature-independent ratiometric response between 0 and 70 °C.

Original languageEnglish
Pages (from-to)1071-1081
Number of pages11
JournalNano letters
Issue number2
Publication statusPublished - Feb 8 2017


  • Ratiometric oxygen sensing
  • core/shell
  • dot-in-bulk nanocrystals
  • dual color emission
  • photocharging
  • pressure sensitive paints

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Single-Particle Ratiometric Pressure Sensing Based on "double-Sensor" Colloidal Nanocrystals'. Together they form a unique fingerprint.

Cite this