For analytical applications, the response time of an ion selective
electrode is a significant issue. The response time of an electrode
indicates the time required by an ion selective electrode to achieve
a steady-state potential (within 71 mV), when it is dipped in
successive analyte ion solution each having the tenfold divergence
in concentration. The dynamic response time of CGE-1 for step
changes in the concentration of Fe (III) ions has been given in Fig.
S4 (Supporting information). It is evident from Fig. S4 that the
time taken for the electrode to achieve 95% of the stable potential
is less than 10 s (approx.) and response time remains constant up
to 5 min. The lifetime of projected CGE-1 was at least 3 months.
During this time, the response characteristics of CGE-1 such as
concentration range (1.0 101
–1.0 107 M), detection limit
(4.68 108 M) and Nernstian slope (18.8 mV/decade) remained
almost constant. After this time period, the electrochemical
behavior of CGE-1 gradually deteriorates, that may be due to
leaching of ionophore (RD) from membrane of CGE-1.
The