A Fluorescent Chemosensor for Sodium Based on Photoinduced Electron Transfer

• Published in: Analytical chemistry (Washington) Vol. 75; no. 3; pp. 549 - 555
• Main Authors: He, Huarui, Mortellaro, Mark A, Leiner, Marc J. P, Young, Susanne T, Fraatz, Robert J, Tusa, James K
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.02.2003
• Subjects: Analytical chemistry; Chemistry; Electrons; Exact sciences and technology; Fluorescence; General, instrumentation; Sensors; Sodium; Performance evaluation; Fluorophore; Sodium; Electron transfer; Optical sensor; Serum; Ionophore; Chemical sensor; Blood
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac0205107

A new optical sensor suitable for practical measurement of sodium in serum and whole blood samples is described. The optical sensor is based on a novel PET (photoinduced eletron transfer) fluoroionophore immobilized in a hydrophilic polymer layer. The design concept of the fluoroionophore follows the receptor-spacer-fluorophore approach to sensor design using intramolecular PET-based signal transduction. Key to the development of this sensor is the identification of a nitrogen-containing, sodium-binding ionophore, coupled with a fluorophore having the correct spectral and electron-accepting properties. The slope of the sensor is ∼0.5%/mM in the typical clinically significant range of 120−160 mM. This sensor has been implemented into a disposable cartridge, used for a commercially available critical care analyzer (Roche OPTI CCA) with precision better than ±1 mM (1 SD). The sensor displays excellent stability against hydrolysis and oxidation, leading to slope changes <5% after 9 months wet storage at 30 °C. On the basis of this design concept, fluoroionophores for other cations such as potassium, calcium and magnesium can be prepared by substitution of the ionophore.