Synthesis and characterization of activated carbon–ethylenediamine–cobalt(II) tetracarboxyphthalocyanine conjugate for catalytic oxidation of ascorbic acid

Moyo, Pamela; Mugadza, Tawanda; Mehlana, Gift; Guyo, Upenyu

doi:10.1007/s11164-016-2477-z

Cited by 9 publications

(2 citation statements)

References 31 publications

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“…Potassium ferrocyanide {K 4 [Fe(CN) 6 ]}, potassium ferricyanide {K 3 [Fe(CN) 6 ]}, sodium hydroxide (NaOH), dimethylformamide (DMF), potassium chloride (KCl), hydrochloric acid (HCl), ascorbic acid (C 6 H 8 O 6 ), l -tryptophan, cobalt chloride (CoCl 2 .6H 2 O), and potassium bromide (KBr) were obtained from ACE; methanol (CH 3 OH) and ethanol (C 2 H 5 OH) were purchased from Glassworld; and trimellitic acid anhydride (C 9 H 4 O 5 ), ammonium chloride (NH 4 Cl), urea [CO(NH 2 ) 2 ], nitrobenzene (C 6 H 5 NO 2 ), hydrochloric acid (HCl), thionyl chloride (SOCl 2 ), tetrahydrofuran (THF), potassium dihydrogen phosphate (KH 2 PO 4 ), ammonium molybdate [(NH 4 ) 2 MoO 4 ], sodium nitrate (NaNO 3 ), potassium permanganate (KMnO 4 ), hydrogen peroxide (H 2 O 2 ), graphite flakes, sulfuric acid (H 2 SO 4 ), and distilled water were locally prepared in the laboratory. The carboxylate-terminated (CoTCPc) and amine-terminated (CoTAPc) phthalocyanines ( Moyo et al, 2016 ; Shumba and Nyokong, 2017 ) and graphene oxide nanosheets were synthesized as reported in the literature.…”

Section: Methodsmentioning

confidence: 99%

“…Though polymerized phthalocyanines have been reported before ( Nyokong and Khene, 2016 ; Liu et al, 2010 ; Sekhosana et al, 2017 ), this work explores for the first time prepolymerization of differently substituted phthalocyanines. This was achieved through amidation of carboxylate- and amine-terminated phthalocyanines as described before ( Moyo et al, 2016 ; Shumba and Nyokong, 2017 ), Scheme 1A . Poly-phthalocyanines (Pcs) are thought to have a higher concentration of the electroactive metal center, hence an enhanced electrocatalytic performance compared to monophthalocyanines (MPcs) ( Nyokong and Khene, 2016 ).…”

Section: Introductionmentioning

confidence: 99%

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Poly-Phthalocyanine–Doped Graphene Oxide Nanosheet Conjugates for Electrocatalytic Oxidation of Drug Residues

et al. 2021

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Donor and acceptor phthalocyanine molecules were copolymerized and linked to graphene oxide nanosheets through amidation to yield electrocatalytic platforms on glassy carbon electrodes. The platforms were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, UV/Vis spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The fabricated electrochemical catalytic surfaces were then evaluated toward electrocatalytic detection of ascorbic acid and tryptophan. These were characterized by a wide linear dynamic range and low limits of detection and quantification of 2.13 and 7.12 µM for ascorbic acid and 1.65 and 5.5 µM for tryptophan, respectively. The catalytic rate constant was 1.86 × 104 and 1.51 × 104 M−1s−1 for ascorbic acid and tryptophan, respectively. The Gibbs energy for catalytic reactions was −17.45 and −14.83 kJ mol−1 depicting a spontaneous reaction on the electrode surface. The sensor platform showed an impressive recovery when applied in real samples such as fresh cow milk, in the range 91.71–106.73% for both samples. The developed sensor therefore shows high potential for applicability for minute quantities of the analytes in real biological samples.

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Section: Methodsmentioning

confidence: 99%