Abstract The effect of component contents and membrane thickness on the detection limit ( DL ), slope ( m ), linear range ( LR ) and response time ( RT ) of Pb 2+ solid contact potentiometric ion selective electrodes (SCISE) based on 4,10‐diaza‐2,3,11,12‐dibenzo‐18‐crown‐6 (1), 4,10‐diaza‐2,3,11,12‐di(4‐ tert ‐butylbenzo)‐18‐crown‐6 (2) and 4,10‐diaza‐2,3,11,12‐dibenzo‐18‐crown‐6‐ N , N ′‐di(carboxymethyl) (3) as ionophores was studied by open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) measurements. The use of an intermediate layer of poly(3‐octyl)thiophene between the gold substrate and the selective membrane was explored. SCISE prepared showing the best responses had typical DL , m , LR and RT values of 10 −6 M, 29 mV/dec, 10 −5 to 10 −3 M and 2 minutes.