Potentiometric sensors based on lipophilic alkylated cyclodextrins exh
ibit a good response to the guanidinium ion, with higher selectivity o
ver sodium than previously reported ionophores; 2,6-didodecyl-beta-cyc
lodextrin has also been shown to exhibit selective response to the gua
nidine derivatives metformin: and phenformin in a simulated clinical e
lectrolyte background.