Nile blue based ion-selective optodes - pH independent ion-selective optical sensing

Description:
Classical approach for cation selective optode sensing requires application of optically silent, analyte selective ionophore together with optical transducer dye (chromoionophore). Typically lipophilic derivative of Nile blue is used, however as this dye is pH sensitive, the sample pH must be strictly controlled and kept close to the dye pKa.
In recent work we have proposed a system that benefits from Nile blue cations applied as optical transducer [1], this dye was previously not considered as optical transducer due to relatively high hydrophilicity. Nile blue, commonly applied as staining agent, is known to show emission dependent on nature of the sample: the phospholipids, nucleic are stain blue, while for neutral lipids pink colour is observed. The dye of choice is Nile blue, on the contrary to chromoionophore is pH insensitive in a broad range.
It was shown that Nile blue can be successfully applied to prepare ion-selective optodes – offering stable sensors, able to operate at pH range typically not accessible for classical chromoionophore based optodes. Moreover, the emission changes are seen at two wavelengths; decrease of emission at ca 650 nm is coupled with increase of emission at ca 600 nm, allowing ratiometric ion-selective optode based sensing

1. A. Konefał, P. Piątek, B. Paterczyk, K. Maksymiuk, A. Michalska Talanta, https://doi.org/10.1016/j.talanta.2022.124038

Speaker: Agata Michalska - University of Warsaw
Agata Michalska is a full professor at the Faculty of Chemistry University of Warsaw (Warsaw, Poland). She has received PhD and DSc (habitation) from the Faculty of Chemistry University of Warsaw. Her research interest is focused on ion-sensors operating using electrochemical or optical principles, in particular on understanding principle and mechanism of their operation, with interest to improve their performance and construction, among others benefiting from nanomaterials. She has published more than 150 papers articles in peer-reviewed journals. She is an associate editor of Talanta.