Electrocatalytic properties of prussian blue nanoparticles supported on poly(m-aminobenzenesulphonic acid)-functionalised single-walled carbon nanotubes towards the detection of dopamine

Abstract

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...

Electrocatalytic Activity of Nanocomposites of Sulphur Doped Graphene Oxide and Nanosized Cobalt Phthalocyanines

“…Figure (A) (using CoPc NP ‐GCE as an example) shows LSV plots obtained after keeping the electrode in a stirred solution for 20 min (to allow for adsorption). Applying the Langmuir adsorption theory (Equation ), a plot of the ratio of hydrogen peroxide concentration to catalytic current against concentration of hydrogen peroxide was linear, which is indicative of adsorption further consolidating the observed high Tafel slopes. …”

“…Using equation 6 which relates Gibbs free energy change due to adsorption (ΔG°) to the adsorption equilibrium constant β, ΔG° was found to be −17.71 k J mol −1 for CoPc NP‐ GCE. This value is comparable to those reported elsewhere for high Tafel slopes . Eqn.…”

A sensitive glucose biosensor based on the abundant immobilization of glucose oxidase on hollow Pt nanospheres assembled on graphene oxide–Prussian Blue–PTC-NH2 nanocomposite film

“…PB, an electron transfer mediator, has been used in the fabrication of our sensor, which catalyses the reduction of hydrogen peroxide in nature [13]. 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 ) [14]. Moreover, previous studies have shown that PB markedly enhanced the performance of carbon composite materials of biosensors [15,16].…”

Prussian Blue/Reduced Graphene Oxide Composite for the Amperometric Determination of Dopamine and Hydrogen Peroxide

“…Dopamine is a well-known catecholamine and a neurotransmitter (Schultz 1997;Komathi, Gopalan, and Lee 2010;Adekunle et al 2012;Dong et al 2012;Pandey and Pandey 2013). Dopamine affects a variety of physiological processes (Adekunle et al 2012).…”

“…Dopamine affects a variety of physiological processes (Adekunle et al 2012). The concentration of dopamine may be determined electrochemically.…”