Fig. 4
Optimization of electrochemical parameters for Hg²⁺ detection using TDA-Trz-POP-modified screen-printed electrodes. (A) Effect of solution type (0.1 M) on the stripping current response of 50 nM Hg²⁺ at pH 5.0 under a deposition potential of − 1.2 V for 280 s.; (B) Influence of solution pH (range: 3–8) on peak current in 0.1 M NaCl. A maximum response was observed at pH 5.0; (C) Variation of accumulation potential (–0.9 V to − 1.3 V) at fixed pH 5.0 and 0.1 M NaCl. Peak current response was highest at − 1.2 V, beyond which water reduction limited performance; (D) Effect of accumulation time (100–300 s) on current response at − 1.2 V in 0.1 M NaCl, pH 5.0.
