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Covalently Anchored p‐Aminobenzene Sulfonate Multilayer on a Graphite Pencil Lead Electrode: A Highly Selective Electrochemical Sensor for Dopamine
Author(s) -
Devaramani Samrat,
Sreeramareddygari Muralikrishna,
Reddy M. Radhakrishna,
Thippeswamy Ramakrishnappa
Publication year - 2017
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201600627
Subject(s) - detection limit , ascorbic acid , differential pulse voltammetry , electrochemical gas sensor , dielectric spectroscopy , electrochemistry , chemistry , electrode , sulfonic acid , buffer solution , cyclic voltammetry , analytical chemistry (journal) , inorganic chemistry , nuclear chemistry , chromatography , organic chemistry , food science
An electrochemical sensor for dopamine (DA) has been developed based on the electrografting of 4‐aminobenzene sulfonic acid (4‐ABSA) onto the graphite pencil lead electrode (GPLE). The process of covalent anchoring and presence of 4‐ABSA on the GPLE was studied using cyclic voltammetry and electrochemical impedance spectroscopy. Electrochemical behaviour of the sensor towards DA, ascorbic acid (AA), and uric acid (UA) was studied in detail in phosphate buffer of pH 7. After optimizing the various parameters that influence the differential pulse voltammetric (DPV) signal for DA, the sensor exhibited a linear response over the 0.5 – 10 μmol⋅L ‐1 concentration range with a limit of detection, 0.095 μmol⋅L ‐1 (at an S/N of 3). The sensor can selectively quantify DA even in the presence of 1 mmol⋅L ‐1 AA. Distinct DPV signals were obtained for DA (at 0.191 mV vs. Ag/AgCl) and for UA (at 0.343 mV vs. Ag/AgCl). The sensor is highly selective, sensitive and stable. It was applied to the quantification of DA in injections and urine. Recovery studies were done by spiking both the real samples with a known quantity of DA.