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Microsensor Chip Integrated with Gold Nanoparticles‐Modified Ultramicroelectrode Array for Improved Electroanalytical Measurement of Copper Ions
Author(s) -
Wang Jinfen,
Bian Chao,
Tong Jianhua,
Sun Jizhou,
Xia Shanhong
Publication year - 2013
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.201300019
Subject(s) - ultramicroelectrode , colloidal gold , copper , nanoparticle , electrode , electrochemistry , analytical chemistry (journal) , detection limit , materials science , voltammetry , nanotechnology , cyclic voltammetry , chemistry , chromatography , metallurgy
This paper presents a microsensor chip integrated with a gold nanoparticles‐modified ultramicroelectrode array (UMEA) as the working electrode for the detection of copper ions in water. The microsensor chip was fabricated with Micro‐Electromechanical System technique. Gold nanoparticles were electrodeposited onto the surface of UMEA at a constant potential of −0.3 V. The ratio d / R b of interelectrode spacing ( d ) over the individual electrode’s radius ( R b ) was investigated to improve the electrochemical performance. The UMEA with a d / R b of 20 showed the best hemispherical diffusion mode, resulted in fast response time and high current response. The gold nanoparticles increased the active surface area of UMEA by not changing the geometries of UMEA, and the current response was increased further. Incorporating the optimized characteristic of UMEA and gold nanoparticles, the microsensor showed a good linear range from 0.5 to 200 µg L −1 of copper ions in the acetate buffer solutions with the method of square wave stripping voltammetry. Compared with the gold nanoparticles‐modified disk electrode, the gold nanoparticles‐modified UMEA showed higher sensitivity (0.024 µA mm −2 µg −1 L) and lower limit of detection (0.2 µg L −1 ). Water samples from river water and tap water were analyzed by the microsensor chip with recovery ranging from 100.7 % to 107.8 %.