A system for probing molecular recognition events at organic interfaces using fluorescent receptors is described. Receptors formed from the bis(2,6-diaminopyridine) amide of isophthalic acid are incorporated in mixed,self-assembled monolayers (SAMs) of alkanethiols on gold and shown to interact with barbituric acid derivatives from solution. Individual parameters that affect the ability of receptors on surfaces to recognize ligands from solution along with varieties of solvents for ligand solutions have been examined.