Electrochemical sensor based on nickel phthalocyanine conjugated polymer for selective detection of p-aminophenol

Abstract

This work reports an advanced, high-efficiency electrochemical sensor for detecting p-aminophenol (p-AP), based on a nickel phthalocyanine polymer containing an S-linker. The nickel phthalocyanine polymer was synthesized via the cyclization reaction with ortho-positioned dicyano groups. The nickel phthalocyanine polymer was drop-coated on GCE to form a modified electrode (PNiPc@GCE), which demonstrated sensitive electrochemical responses. Optimal conditions for preparing the modified electrode and detecting p-AP were selected through electrochemical experiments. Cyclic voltammetry (CV) curves at different rates (20 mV s⁻¹ ∼ 200 mV/s) indicated that the oxidation of p-AP follows a diffusion-controlled process on the surface of the PNiPc@GCE electrode. The p-AP, in the range of 0.1 ∼ 1000 μM, was detected using DPV curves, displaying a good linear response under optimal conditions. The sensitivity was determined to be 21.70 mA µM⁻¹ cm⁻², and the LOD was 20 nM (S/N = 3). Furthermore, the recovery experiments were conducted at different concentration levels in practical water samples, showing relatively satisfactory recoveries and indicating the potential of the PNiPc@GCE sensor for quantitative detection of p-AP molecules in practical applications. Following storage at room temperature for eight weeks, the sensor remained at 95 % of its original peak current, with negligible interference. Therefore, the developed sensor made a valuable contribution to advancing electrochemical sensing technology and its application in the environment.