Study On The Structure And Electrochemical Sensitivity Of Cationic Phthalocyanine / Carbon Composites

In this paper, three metal phthalocyanines, viz tetra-β-[3-(dimethylamino)phenoxy] phthalocyanine cobalt(II)(aPcCo), tetra-β-(N,N-dimethylaminoethoxy)phthalocyanine cobalt(II)(ePcCo) and tetra-β-(N,N-diethylaminoethoxy)phthalocyanine cobalt(II)(mPcCo),were synthesized by template-reaction method at the present of 1,8-diazabicyclo[5,4,0]undec-7-ene.Then, ePcCo and mPcCo were methylation reaction by methyl iodide, prepared the corresponding cationic cobalt phthalocyanine, ePcCoMet and mPcCoMet. The products and their intermediates were characterized by 1H NMR, MALDI-TOF-MS, FT-IR, UV-VIS, Raman, XPS, SEM and TEM,respectively and build two kinds of PcCo/acidification carbon nanotube composites and one kind of PcCo/ electro-reduction of graphene oxide composites, namely aPcCo/CNT,(ePcCoMet/CNT)10 and(mPcCoMet/ERGO)10, respectively.Three kinds of detection of phenols electrochemical sensors was designed and prepared by immobilization of the as-prepared composites on the suface of the glassy carbon electrode via the drop coating method and layer-by-layer self-assembly method. The electrocatalytic behaviors of the composite modified electrodes were investigated. The results are as follws:(1) The electrochemical sensor for 4-aminophenol(4-AP) based on aPcCo/CNT. The results of various characterizations revealed that the successful self-assembly between a PcCo and CNT via π-π stacking interaction. The electrocatalytic activity of the aPcCo/CNT/GC electrode towards 4-AP was investigated by cyclic voltammetry(CV). To highlight the effect of hydrogen ion concentration on the electrocatalytic activity of 4-AP, CVs at different pH values indicate that the number of protons and electrons involved in the electrochemical redox processes of 4-AP are equal.(2) The electrochemical sensor for 4-nitrophenol(4-NP) based on(ePcCoMet/CNT)10 is designed. Layer-by-layer(LBL) multilayers of CNT and ePcCoMet have been assembled on electrode surfaces. According to the cyclic voltammograms measurement, the(ePcCoMet/CNT)10 composite film displays good electrocatalytic activity for the oxidation of 4-NP. Compared to the bare electrode, the modified electrode demonstrated a 4-NP better electrocatalytic activity and reduces the 4-NP overpotential.(3) The electrochemical sensor for catechins(CC) based on mPcCoMet and electrochemically reduced graphene oxide(ERGO) functional multilayer films, which are prepared by the alternating layer-by-layer(LBL) assembly of negatively charged graphene oxide(GO) and positively charged mPcCoMet in combination with an electrochemical reduction procedure. The results show that the modified electrode to CC has excellent electrochemical response performance, comparing the response current of CC after adding interferents with that in the absence of interferents, it is clear that the interferents had no impact on the CC detection performance.