Fluorescent ion optodes based on calixarene functionized boron dipyrromethene chromoionophore for simultaneous measurement of multi-electrolytes in biological samples

A calix[4]arene functionized boron dipyrromethene (CBDP) was utilized as a charged fluorescent chromoionophore in ion optodes. The plasticized polyvinyl chloride (PVC) films containing CBDP and anion exchanger tridodecylmethylammonium chloride (TDMACl) exhibited reversible response to pH from 2 to 10. The fluorescence intensity of CBDP increases upon protonation due to the suppression of the photo induced electron transfer (PET) process between phenolate anion in calixarene and bodipy core. CBDP was applied to prepare anion and cation selective optodes based on co-extraction or ion-exchange mechanism. Optical sensors with the same fluorescent chromoionophore for four blood electrolytes, chloride ion, potassium ion, sodium ion, and calcium ion were prepared and allow the simultaneous measurements of multi analytes in biological samples by microplate reader. The concentrations of four electrolytes in rabbit plasma determined by the proposed optodes were consistent with the results obtained by conventional potentiometric methods, which suggests the possibilities for further applications of such optodes in clinical diagnosis.