Abstract
<p class="PaperAbstract">A simple, disposable and low - cost voltammetric sensor based on the anodized pencil graphite electrode (APGE) for the simultaneous determination of dopamine (DA) and uric acid (UA) is demonstrated. The physico-chemical properties of the pencil graphite electrode (PGE) before and after anodization were analyzed using FT-IR, FT-Raman, SEM and EIS characterization techniques. In comparison to PGE, APGE exhibited excellent electrochemical activity towards the simultaneous detection of DA and UA with peak-to-peak separation of about 0.18 V even in the presence of high concentration (2 mM) of ascorbic acid (AA). The discrimination of APGE towards AA was rationalized through the absence of favorable surface interactions between oxygen rich functional groups on the surface of APGE and AA. Using DPV without any pre-concentration step and under optimized conditions, APGE displayed a linear range of 1 – 80 μM with an estimated limit of detection (LOD, 3σ/m) of 0.008 μM and 0.014 μM for DA and UA, respectively. Moreover, a higher sensitivity in comparison to other previously reported pretreated pencil graphite electrodes was observed for DA (34.32 μA/μM) and UA (12.33 μA/μM). The practical applicability of APGE was demonstrated through the estimation of DA in human blood serum and UA in urine samples.</p>
Highlights
Several diseases such as Lysch – Nyhan syndrome, hyperuricaemia and gout are the consequences of abnormal levels of uric acid (UA) [5,6,7,8,9,10]
It is a well-established fact that anodization of carbon surface leads to the creation of surface defects due to the formation of oxygen rich functional groups such as -COOH, -OH, etc. [27,40]
The characteristic peaks at 3144 cm-1 (O–H stretching from COOH), 1662 cm-1 (C=C stretching), 1394 cm-1 (C=C bending) and 1088 cm-1 (C–O stretching from COOH) indicate the successful modification of pencil graphite electrode (PGE) surface with these functional groups [41,42]
Summary
Dopamine (DA) is one of the neurotransmitters in the family of catecholamines, which exists as organic cations in brain tissues and body fluids. Like DA, uric acid (UA) is another class of biomolecules which forms in the body as one of the principal end-products of the purine metabolism. Several diseases such as Lysch – Nyhan syndrome, hyperuricaemia and gout are the consequences of abnormal levels of UA [5,6,7,8,9,10]. Accurate detection of DA and UA in body fluids like blood serum and urine is of great clinical importance for an effective point of care analysis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
