Premium
Polythymine Oligonucleotide‐Modified Gold Electrode for Voltammetric Determination of Mercury(II) in Aqueous Solution
Author(s) -
Wu Jikui,
Li Lanying,
Shen Bijun,
Cheng Guifang,
He Pingang,
Fang Yuzhi
Publication year - 2010
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.200900441
Subject(s) - electrode , dropping mercury electrode , chemistry , detection limit , saturated calomel electrode , supporting electrolyte , reference electrode , aqueous solution , electrochemistry , selectivity , quinhydrone electrode , inorganic chemistry , anodic stripping voltammetry , analytical chemistry (journal) , working electrode , standard hydrogen electrode , chromatography , organic chemistry , catalysis
Abstract Polythymine oligonucleotide (PTO)‐modified gold electrode (PTO/Au) was developed for selective and sensitive Hg 2+ detection in aqueous solutions. This modified electrode was prepared by self‐assembly of thiolated polythymine oligonucleotide (5′‐SH‐T 15 ‐3′) on the gold electrode via AuS bonds, and then the surface was passivated with 1‐mercaptohexanol solution. The proposed electrode utilizes the specific binding interactions between Hg 2+ and thymine to selectively capture Hg 2+ , thereby reducing the interference from coexistent ions. After exchanging the medium, electrochemical reduction at −0.2 V for 60 s, voltammetric determination was performed by differential pulse voltammetry using 10 mM HEPES; pH 7.2, 1 M NaClO 4 as supporting electrolyte. This electrode showed increasing voltammetric response in the range of 0.21 nM Hg 2+ , with a relative standard deviation of 5.32% and a practical detection limit of 60 pM. Compared with the conventional stripping approach, the modified electrode exhibits good sensitivity and selectivity, and is expected to be a new type of green electrode.