MWCNTs-Ionic Liquids-Ionophore-Graphite Nanocomposite Based Sensor for Selective Determination of Ytterbium(III) Ion

Abstract

Fluorescence studies in acetonitrile solution proved a strong interaction between N'-(1-oxoacenaphthylen-2(1H)-ylidene) furan-2-carbohydrazide (L) with Yb3+ ions in comparison with other lanthanide ions. Thus, L can be used as a suitable ionophore in construction of the Yb3+ potentiometric sensor. To have an electrode with enhanced mechanical resistant in real samples, L was used as a sensing material in new composite carbon paste electrode. The carbon paste were made based on a new nano-composite including multi-wall carbon nanotube (MWCNT), and room temperature ionic liquid, 1-n-butyl-3-methylimidazolium tetrafluoroborate [bmim]BF4. The nano-composite electrode showed better sensitivity, selectivity, response time, response stability and lifetime in comparison with typical carbon paste electrodes. The best performance for nano-composite sensor was obtained with electrode composition of 25% L, 25% [bmim]BF4, 45% graphite powder, and 5% MWCNT. The new electrode exhibited a Nernstian response (19.6±0.3 mV per decade) toward Yb3+ ions in the range of 1.0×10-8-1.0×10-2 mol L-1