The supercapacitive properties of nickel(II) tetraaminophthalocyanine (NiTAPc)/multi-walled carbon nanotube (MWCNT) nanocomposite films have been interrogated for the first time and found to possess a maximum specific capacitance of 981 AE 57 F g À1 (200 AE 12 mF cm À2 ), a maximum power density of 700 AE 1 Wkg À1 , a maximum specific energy of 134 AE 8 Wh kg À1 and excellent stability of over 1500 charge-discharge continuous cycling. Impedimetric study proves that most of the stored energy of the MWCNT-NiTAPc nanocomposite can be accessible at high frequency (720 Hz). When compared to MWCNTs modified with unsubstituted nickel(II) phthalocyanine (MWCNT-NiPc) or nickel(II) tetratert-butylphthalocyanine (MWCNT-tBuNiPc), MWCNT-NiTAPc exhibited superior supercapacitive behaviour, possibly due to the influence of nitrogen-containing groups on the phthalocyanine rings.

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Edged plane pyrolytic graphite electrode (EPPGE) was modified with and without Prussian blue (PB) nanoparticles and polyaminobenzene sulphonated single-walled carbon nanotubes (SWCNTPABS) using the chemical deposition method. The electrodes were characterised using microscopy, spectroscopy and electrochemical techniques. Results showed that edged plane pyrolytic graphite-single-walled carbon nanotubes-prussian blue (EPPGE-SWCNT-PB) electrode gave the best dopamine (DA) current response which increases with increasing PB layers. The catalytic rate constant of 1.69 x 10 5 mol -1 cm 3 s -1 , Tafel value of 112 mVdec -1 , and limit of detection of DA (2.8 nM) were obtained. Dopamine could be simultaneously detected with ascorbic acid. The electrode was found to be electrochemically stable, reusable and can be used for the analysis of DA in real drug samples.Keywords: Prussian blue nanoparticles; Dopamine; Electrochemical impedance spectroscopy; Interferences; Ascorbic acid IntroductionCarbon nanotubes (CNTs) are excellent electrical conducting nanowires with unique properties such as high tensile strength, electrical conductivity, chemical stability and flexibility. They are essential and promising materials in the field of nano-science and nanotechnology because of their electronic properties and large surface area [1][2][3]. Their contribution to the improvement of electrical properties of some bare electrode such as the glassy carbon [4][5][6], graphite [7][8][9][10], carbon fiber [11], gold [12][13][14][15], and platinum (Pt) electrodes [16] have been reported. As part of its numerous applications, Han et al. [17] considered CNTs as suitable mediators for prussian blue (PB)-modified electrodes because of their good electrical conductivity and the property of being particle carriers.Prussian blue (PB) is a polynuclear and mixed-valent iron cyanide complex with a repeating unit of potassium ferrous ferricyanide hexacyano hexahydrate (Fe 4 (III) [Fe(II) (CN) 6 ] 3 ) . Prussian blue has unique properties in its structural arrangement which allows compositional variation by combining with several transition metal ions in different oxidation states such as Co 2+ , and Co 3+ , and Ni 2+ [18]. This metal substitution and variation leads to a combination of properties that are not readily found in other inorganic materials [19]. Its unique properties, synthetic versatility and the ability of the cyanide ligands to bridge other ions have been explored in its application in electrochromic devices [20] Equipment and ProcedureThe edge plane pyrolytic graphite electrode plate (3 mm diameter) was purchased from Le Carbone, Sussex, UK and was constructed locally at the University of Pretoria technical workshop. The plate was placed in a teflon tube, extended outside with a copper wire to make electrical contact with the electrochemical equipment. The energy dispersive X-ray spectra were Ag|AgCl in sat. KCl). An Ag|AgCl in saturated KCl and platinum wire were used as reference and counter electrodes, respectively...

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Manganese tetrakis (benzyl-mercapto) phthalocyanine (MnTBMPc) and manganese tetrakis (dodecyl-mercapto) phthalocyanine (MnTDMPc) complexes were synthesized and their spectral and electrochemical properties are reported. Cyclic voltammetric data showed three reversible to quasi-reversible and two irreversible redox processes for both complexes. Ring substituents influenced the positions of both oxidation and reduction redox couples. Spectroelectrochemistry confirmed the first two reductions to be due to Mn The first example of a formation of self-assembled monolayers (SAMs) using thiol substituted MnPc complexes is presented, the SAMs were found to show blocking characteristics towards some faradaic reactions.