Selectivity coefficients of the Pb(ii) sensor in presence of other ions.

Foreign ion	K SSM	K FIM
Ni2+	3.13 × 10−4	3.16 × 10−4
Cd2+	9.91 × 10−4	4.83 × 10−3
Co2+	4.25 × 10−4	9.25 × 10−4
Cu2+	9.90 × 10−4	2.24 × 10−4
Mn2+	9.88 × 10−5	8.53 × 10−5
Zn2+	1.15 × 10−4	9.95 × 10−5
Cr3+	3.14 × 10−4	3.01 × 10−5
Al3+	1.35 × 10−4	1.60 × 10−4
Fe3+	2.14 × 10−4	1.58 × 10−4
Hg2+	7.94 × 10−4	9.65 × 10−4
Ca2+	5.77 × 10−5	5.01 × 10−4
Mg2+	4.58 × 10−5	8.03 × 10−5
Na+	4.60 × 10−2	8.01 × 10−2
K+	1.14 × 10−2	7.89 × 10−2