Selective determination of 3,4-dihydroxyphenylacetic acid in the presence of ascorbic and uric acids using polymer film modified electrode

Abstract

We report here the highly sensitive and selective electrochemical determination of 3,4-dihydroxyphenylacetic acid (DOPAC), one of the dopamine metabolites in the presence of important interferents ascorbic acid (AA) and uric acid (UA) using an ultrathin electropolymerized film of 5-amino-1,3,4-thiadiazole-2-thiol (p-ATT) modified glassy carbon (GC) electrode in 0.20 M phosphate buffer solution (pH 5.0). The bare GC electrode fails to resolve the oxidation peaks of AA, DOPAC and UA in a mixture. Further, the oxidation peak potentials of them were shifted to more positive potential with decreased peak currents in the subsequent cycles. On the other hand, the p-ATT modified electrode not only separated the voltammetric signals of AA, DOPAC and UA but also enhanced their peak currents. The amperometric current response was increased linearly with increasing DOPAC concentration in the range of 4.0 × 10 −8 to 1.0 × 10 −5 M and the detection limit was found to be 150 pM (S/N = 3).

Determination of gallic acid using poly(glutamic acid): graphene modified electrode

“…13 Recent research has focused attention towards polymer-modified electrodes as they possess propitious characteristics such as more active sites, excellent perm-selectivity, good stability and strong adherence towards electrode surface. 14,15 Biopolymers prove to be more promising sensing platform in comparison to synthetic polymers as they are bio-compatible and biodegradable. [16][17][18] Poly-Glutamic acid (Poly-Glu) is one such biopolymer with various biological functions and promising properties for basic and applied research.…”

Fabrication of β‐Cyclodextrin/Glycine/Carbon Nanotubes Electrochemical Neurotransmitters Sensor – Application in Ultra‐sensitive Determination of DOPAC in Human Serum

“…Furthermore, the sensor was used to examine the voltammetry response toward 1 mmol L −1 DOPAC/0.1 mmol L −1 PBS/pH 7.4 for four different measurements. Small relative standard deviations of 0.742 % and 0.707 % were obtained for reproducibility and repeatability, respectively which are lower than that reported in literature . Good reproducibility and repeatability can be achieved at the proposed sensor toward DOPAC determination.…”

“…As neurotransmitters are fundamental to secure human health from the dangerous diseases therefore, it is important to develop a new strategy that facilitates their determination in biological fluids in an easy, rapid and sensitive manner. On the other hand, DOPAC is formed in human and animal organisms by the oxidative deamination of DA catalyzed by monoamine oxidase which formed during the quercetin degeneration by colonic bacteria [15]. Determination of DOPAC has been carried out by several techniques such as liquid chromatography [16], fluorometry [17], capillary electrophoresis [18] and HPLC [2,[19][20][21].…”

Simultaneous determination of two important dopamine metabolites at physiological pH by voltammetry

“…Compared to these methods, the electrochemical method is less expensive, more convenient and highly selective and sensitive. Although a few reports were available in the literature for the individual determination of DOPAC [15][16][17][18][19][20][21][22] and HVA [23][24][25][26] by the electrochemical method, no report was available for their simultaneous determination. Thus, the objective of the present work is to determine DOPAC and HVA simultaneously using the electropolymerized film of a 3-amino-5-mercapto-1,2,4-triazole modified (p-AMTa) electrode by voltammetry.…”

“…The reported detection limits of DOPAC [15][16][17][18][19][20][21][22] and HVA 23,24 at different modified electrodes are compared with the present modified electrode and are given in Tables 1 and 2. As can be seen from the tables, the p-AMTa electrode showed the lowest detection limit for both DOPAC (66 nM) and HVA (94.2 pM).…”