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Electrochemical Oxidative Detection of Guanosine‐5′‐triphosphate Based on a New Ionic Liquid Modified Carbon Paste Electrode
Author(s) -
Shi Fan,
Zhu Huanhuan,
Li Linfang,
Ling Luyang,
Sun Wei
Publication year - 2013
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.201300080
Subject(s) - chemistry , charge transfer coefficient , gtp' , carbon paste electrode , electrochemistry , electrode , detection limit , electron transfer , cyclic voltammetry , inorganic chemistry , differential pulse voltammetry , guanosine , adsorption , analytical chemistry (journal) , nuclear chemistry , chromatography , organic chemistry , biochemistry , enzyme
An ionic liquid (IL) 1‐(3‐chloro‐2‐hydroxy‐propyl)‐3‐methylimidazolium trifluoroacetate was used as the modifier for the preparation of the modified carbon paste electrode (CPE). The IL‐CPE showed excellent electrocatalytic activity towards the oxidation of guanosine‐5′‐triphosphate (5′‐GTP) in a pH 5.0 Britton‐Robinson buffer solution. Due to the presence of high conductive IL on the electrode surface, the electrooxidation of 5′‐GTP was greatly promoted with a single well‐defined irreversible oxidation peak appeared. The electrode reaction was an adsorption‐controlled process and the electrochemical parameters of 5′‐GTP on IL‐CPE were calculated with the electron transfer coefficient (α) as 0.44, the electron transfer number ( n ) as 1.99, the apparent heterogeneous electron transfer rate constant ( k s ) as 2.21 × 10 −9 s −1 and the surface coverage (Γ T ) as 1.53 × 10 −10 mol cm −2 . Under the selected conditions a linear calibration curve between the oxidation peak currents and 5′‐GTP concentration was obtained in the range from 2.0 to 1000.0 μmol L −1 with the detection limit as 0.049 μmol L −1 (3σ) by differential pulse voltammetry. The proposed method showed good selectivity to the 5‘‐GTP detection without the interferences of coexisting substances and the practical application was checked by measurements of the artificial samples.