Nanomolar Detection Of Mercury(Ii) Using Electropolymerized Phthalocyanine Film

The synthesis and characterization of novel cobalt(II) tetraamide benzimidazole phthalocyanine (CoTABImPc) has been reported for the first time and applied for the determination of mercury(II) at nanomolar concentration using electrochemical techniques. CoTABImPc was prepared by coupling 4-(1H-benzimidazol-2-yflaniline with cobalt(II) tetracarboxylic acid phthalocyanine. CoTABImPc was characterized by elemental analysis, TGA, FT-IR, UV-visible, Mass, and NMR spectroscopic techniques. The CoTABImPc was electropolymerized on clean glassy carbon electrode (GCE) by continuous cycling of the potential (GCE/poly(CoTABImPc)). The polymeric film was employed for the detection of highly toxic Hg(II) by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometric (CA) methods. The designed GCE/poly(CoTABImPc) electrode exhibited good electrochemical response and high electrocatalytic activity for detecting Hg(II). The Pc polymeric film electrode displayed a sensitivity of 1.2178 mu A nM(-1) cm(-2) for the detection of Hg(II) in the linear range 10-300 nM, and low detection limit of 4 nM using CV technique. Further, DPV exhibited a sensitivity of 1.4024 mu A nM(-1) cm(-2) in the 10-500 nM range with LOD of 3.8 nM. The CA method delivered an excellent sensitivity of 3.7389 mu A nM(-1) cm(-2) in the linear range 10-400 nM with LOD of 3 nM. The proposed method augments the selective electrochemical determination of Hg(II) in environment pollution analysis. (C) 2020 Elsevier Ltd. All rights reserved.