Premium
Detection of Thiols by o ‐Quinone Nanocomposite Modified Electrodes
Author(s) -
Devasurendra Amila M.,
Zhu Tianxia,
Kirchhoff Jon R.
Publication year - 2016
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.201600334
Subject(s) - amperometry , pyrroloquinoline quinone , detection limit , cyclic voltammetry , thiol , polypyrrole , glassy carbon , electrode , chemistry , nanocomposite , electrochemistry , biosensor , nuclear chemistry , inorganic chemistry , materials science , chromatography , organic chemistry , nanotechnology , enzyme , cofactor , biochemistry
A chemically modified glassy carbon (GC) electrode was developed as an amperometric sensor for detection of biological thiols. The electrode was modified by inclusion of co‐enzyme pyrroloquinoline quinone (PQQ) and a co‐catalyst of oxidized single wall carbon nanotubes (Ox‐SWNT) into a gold polypyrrole (Au‐PPy) nanocomposite matrix. The electrode (PQQ/Ox‐SWNT/Au‐PPy/GC) was characterized using scanning electron microscopy and cyclic voltammetry. Optimal conditions for the PQQ/Ox‐SWNT/Au‐PPy/GC electrode were determined and then utilized for the amperometric detection of L ‐cysteine, N ‐acetyl‐ L ‐cysteine, L ‐penicillamine and D , L ‐glutathione. The electrochemical response for each thiol in pH 3.2 citrate phosphate buffer at +450 mV (vs. Ag/AgCl) was found to be linear with limit of detections (LOD, S/N=3) ranging from 0.50 µM for L ‐penicillamine to 1.55 µM for D , L ‐glutathione with sensitivities of 30.2 nA/µM and 3.6 nA/µM respectively. The electrode design is simple and easy to construct using a minimum amount of co‐enzyme and co‐catalyst, resulting in detection methods with very good stability and improved sensitivity for thiol detection.