Phosphorous (V) Corrole Fluorophores for Nitrite Assessment in Environmental and Biological Samples

Two phosphorous (V) corrole complexes, [5,10,15-pentafluorophenyl corrole] phosphorous (V) (PFCorr) and [10-(4-trimethylsilylphenyl)-5,15-dimesityl-corrole] phosphorous (V) (PCorr) were synthesized and tested as nitrite-sensitive fluorophores. Fluorimetry studies on ligand sensitivity towards anions were carried out in solution, then inside polymeric membrane optodes deposited on glass, and finally by functionalized SiO2 nanoparticles deposited on a paper support. The selective fluorescence quenching was registered upon addition of an increasing amount of NO2- ions for both ligands. The influence on the PFCorr optode's response of the lipophilic sites' functionalization was investigated. The sensors' suitability for nitrite assessment in natural waters at levels 10-fault lower than the WHO's recommended maximum concentration level of 3 mg/L was demonstrated.

Automated summary

Two phosphorous (V) corrole complexes were synthesized and tested as nitrite-sensitive fluorophores. The selective fluorescence quenching ability of both complexes upon addition of NO2- ions was demonstrated. The functionalization of the optode's lipophilic sites was found to influence its response. These sensors were proven suitable for nitrite detection in natural waters.