The complexation mode of metal ions with Langmuir monolayers of nitrogen-containing flavonoid glycoside-based surfactants derived from rutin

► Selective complexation for RuCn to metal ions at the interface is studied. ► RuCn can chelate with soft metal ions more easily than those of the hard metal ions. ► The metal-RuCn monolayer stability is enhanced as the lipid chain length increases. ► Two typical surface molecular configurations on air-electrolyte subphases are clarified.