Reversible Oxygen Sensing Based on Multi-Emission Fluorescence Quenching

Reversible Oxygen Sensing Based on Multi-Emission Fluorescence Quenching

Blog Article

Oxygen is ubiquitous in nature and it plays a key role in several biological processes, such as cellular respiration and food deterioration, to name a few.Currently, reversible and non-destructive oxygen sensing is usually performed with sensors produced by photosensitization of phosphorescent organometallic complexes.In contrast, we propose a novel route of optical oxygen sensing by fluorescence-based quenching of oxygen.We hereby developed for the first time a set of multi-emissive purely organic emitters.

These were produced through a one-pot hydrothermal synthesis using p-phenylenediamine (PPD) and urea as starting materials.The origin of the multi-emission has been ascribed to the diversity of chemical structures produced as a result of oxidative oligomerization of PPD.A Bandrowski’s base (BB, i.e.

, trimer of PPD) is reported as the Men Care main component at reaction times higher than 8 h.This indication was confirmed by electrospray-ionization quadrupole time-of-flight (ESI-QTOF) and liquid chromatography-mass spectrometry (LC-MS) analysis.Once the emitters are embedded within a high molecular weight poly (vinyl alcohol) matrix, the intensities of all three emission centers exhibit a non-linear quenching provoked by oxygen within the range of 0−8 kPa.The detection limit of the emission centers are 0.

89 kPa, 0.67 kPa and 0.75 332 kPa, respectively.This oxygen-dependent change in fluorescence emission is reversible (up to three tested 0−21% O2 cycles) and reproducible with negligible cross-interference to humidity.

The cost-effectiveness, metal-free formulation, cross-referencing between each single emission center and the relevant oxygen range are all appealing features, making these sensors promising for the detection of oxygen, e.g., in food packaged products.