Abstract
Onleavefrom:DepartmentofChemistry,FacultyofScience,Ain-ShamsUniversity,Cairo,EgyptReceived:November18,2002Finalversion:March5,2003AbstractIon-selectiveelectrodesbasedontheionophore[9]mercuracarborand-3(MC3)havebeendemonstratedinthepasttobehighlyselectiveforthechlorideion.ThisionophoreismacrocyclicandpossessesLewisacidicmercurycenters,both of which result in enhanced ionophore binding to spherical anions. Like their charge-reverse analogs, crownethers,mercuracarborandsofferthepossibilitytotunebindingselectivitythroughchangesincavitysizeand/orviatheincorporationoffunctionalgroupsontothecavityframework.Indeed,thisarticleoutlinestheeffectonionophoreselectivitythatresultsfromtheadditionofmethylgroupstotheMC3×scarboranecages.Ourresultsindicatethatthissimple functionalization leads to significant changes in selectivity that can be attributed to electronic effects.Furthermore, since MC3-based electrodes and optodes have previously shown sufficient selectivities to performphysiologicalanalysis,theeffectofproteinbackgroundsandmildexposuretohumanwholebloodontheresponseofmercuracarborandISEsisalsoreported.Keywords:Mercuracarborands,Ion-selectiveelectrodes,Chloride,ISE-proteininteractions
