P1OS.9 - Ion-selective optode microsensors based on hydrophobic solvatochromic dyes
- Event
- 17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
Vienna, Austria - Chapter
- P-1 - Optical Sensors
- Author(s)
- L. Wang, S. Sadler, E. Bakker - Department of Inorganic and Analytical Chemistry, University of Geneva, Geneva (Switzerland)
- Pages
- 633 - 634
- DOI
- 10.5162/IMCS2018/P1OS.9
- ISBN
- 978-3-9816876-9-9
- Price
- free
Abstract
Traditional ion-selective optodes based ion-exchange progress typically use a lipophilic pH indicator (also called chromoionophore) and give a cross response to sample pH changes, which has been very difficult to overcome until the introduction of electrically charged solvatochromic dyes (SDs). However, water soluble SDs are expelled to the aqueous phase during the ion-exchange progress, which is undesired. To solve this limitation, hydrophobic solvatochromic dyes are introduced. They localize the ion-exchange process for ion-selective optodes, rendering them pH independent while avoiding dye leakage. Structurally different lipophilized solvatochromic dyes are presented here for this purpose. Sensors containing SDs with a hydrophilic oxyethylene group are more sensitive and have lower detection limit compared to SDs with hydrophobic alkyl groups. Their response range can be successfully tuned by the choice of the dye so that they are potentially more attractive for on site, bioanalytical and imaging applications.