In order to research the competitive binding with CaM between metal ions and Ca~(2+),electrochemical impedance spectroscopy(EIS)of ion(such as Ca~(2+),Cd~(2+),Al~(3+),Fe~(3+))-loaded CaM self-assembled membrane on Au electrode in 0.15mol/L NaCl solution containing 2mmol/L [Fe(CN)_6]~(3-/4-) at pH 6.5is investigated.The results indicate that the ion-binding property of CaM can be detected by the change of the electrochemical reaction resistance.Ca~(2+),Cd~(2+)and Al~(3+)can combine with CaM,and Fe~(3+)can't ...