Determination of Dopamine by Dual Doped Graphene-Fe₂O₃in Presence of Ascorbic Acid

Abstract

Both nitrogen and sulfur dual doped graphene supported Fe 2 O 3 (NSG-Fe 2 O 3 ) have been prepared by hydrothermal methods and subsequently utilized for the electrochemical determination of dopamine (DA) in presence of ascorbic acid (AA). The NSG-Fe 2 O 3 has been characterized via transmission electron microscopy (TEM) and X-ray photoelectron spectroscopic (XPS). The electrochemical detection of DA was measured through the cyclic voltammetry, differential pulse voltammetry, and amperometric techniques in a 0.1 M phosphate buffer solution (PBS) at pH 7.4. Interferences have been investigated in presence of AA, glucose, serotonin, N 2 H 4 , and uric acid. The NSG-Fe 2 O 3 has shown good analytical performance for DA with comparatively better sensitivity (29.1 μA mM −1 ), long linear detection range (0.3-210 μM) and detection limit (0.035 μM) (S/N = 3). The catalytic rate constant for DA detection has been calculated as 9.6 × 10 4 M −1 s −1 with a good diffusion coefficient of 3.5 × 10 −4 cm 2 s −1 . The electrooxidation of DA may enhances by fast proton acceptance and/or electron donation due to higher electron density for excess loan pair electron that provided from N and S dual-doped graphene sheets. 3,4-dihydroxyphenyl ethylamine (dopamine, DA) plays a significant role as a neurotransmitter in the function of the central nervous, renal and hormonal system. Low levels or abnormalities in DA concentration may lead to several neurological diseases, such as schizophrenia, Parkinson's disease, attention deficit hyperactivity disorder, restless legs syndrome and drug addiction.1-4 It is, however, several analytical techniques have been developed for DA detection, including high performance liquid chromatography, 5 chemiluminescence 6 and gas chromatography-mass spectrometry, 7 but each technique has several disadvantages. On the other hand, electrochemical sensing is preferred alternative method because of simple operation, fast response, time savings, low-cost, high-sensitivity and excellent selectivity. [8][9][10][11] Nevertheless, the electrochemical determination of DA is generally hindered by high concentration ascorbic acid (AA) which is another electroactive species that plays an important role in human metabolism and interfering species for DA sensing. Through the electrochemical method, it is difficult to sense DA selectively in the presence of high concentration AA, because these two species are responding nearly the same oxidation potential on the bare electrode, resulting in poor selectivity and sensitivity of DA detection. 12Graphene sheets are highly conductive and have 2D flat lattices consisting of a monolayer of sp 2 -hybridized carbon atoms. Due to high electrical conductivity and electron mobility, large surface area, long-term stability and unique mechanical flexibility, 13-15 graphene has attracted a great deal of research interest. Graphene has already been used in various fields, especially in catalysis, and sensors. [16][17][18][19][20][21][22][23] The graphene sheets can be readily synthesiz...

Graphene Supported Silver Nanocrystals Preparation for Efficient Oxygen Reduction in Alkaline Fuel Cells

“…[31][32][33][34] For the preparation of reduced graphene oxide (rGO) via chemical reduction, however, reducing agents such as, hydrazine (N 2 H 4 ), 35,36 N,N-dimethylhydrazine, 37 hydroquinone 38 and sodium borohydride (NaBH 4 ) 39 have been used. Unfortunately, because of their toxic and explosive properties, safety precautions must be taken when large quantities of these reagents are used.18,34 Also, some reductants like N 2 H 4 or thermal treatment (in presence of other foreign molecules) are often introduces heteroatoms into the graphene z E-mail: ybkim@chonnam.ac.kr plane to produce doped graphene 40,41 that could show certain ORR activities with losing the purity of graphene.42 Moreover, particular reducing agent has the specific oxygenated group removal efficiency. For example, the Nagase group 43 has found that the N 2 H 4 and thermal treatment could efficiently remove the epoxide group (plane) than −COOH (edge) from GO.…”

“…18,34 Also, some reductants like N 2 H 4 or thermal treatment (in presence of other foreign molecules) are often introduces heteroatoms into the graphene z E-mail: ybkim@chonnam.ac.kr plane to produce doped graphene 40,41 that could show certain ORR activities with losing the purity of graphene.…”

“…Unfortunately, because of their toxic and explosive properties, safety precautions must be taken when large quantities of these reagents are used. 18,34 Also, some reductants like N 2 H 4 or thermal treatment (in presence of other foreign molecules) are often introduces heteroatoms into the graphene z E-mail: ybkim@chonnam.ac.kr plane to produce doped graphene 40,41 that could show certain ORR activities with losing the purity of graphene. 42 Moreover, particular reducing agent has the specific oxygenated group removal efficiency.…”

Synthesis of an ordered nanoporous Fe2O3/Au film for application in ascorbic acid detection

“…12,[20][21][22][23] In contrast, it can be found in Fig. Firstly, Fe 2 O 3 is an ideal sensor material due to its proper redox potentials.…”

“…[14][15][16] In the last few years, researches on the growth and properties of Fe 2 O 3 nanomaterials have increased steadily. [20][21][22][23] Au nanostructures are also interest for the electrochemical detection of analytics in physiological fluids because of their stability, oxidation resistance, electronic conductivity and biocompatibility. [17][18][19] Since the discovery of the size-dependent peroxidase-like activity of Fe 3 O 4 nanoparticles, iron oxide based materials for the electrochemical sensors have been intensively studied.…”