Printed microelectrode array and amperometric sensor for environmental monitoring

✍ Scribed by B.J. Seddon; Y. Shao; H.H. Girault

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 966 KB
• Volume: 39
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(94)e0184-p

✦ Synopsis

A disposable electrochemical sensor for the determination of heavy metal traces has been designed for environmental field analysis . The sensor is supported on a polycarbonate film and consists of an amperometric transducer in combination with an adjacent silver-ink reference electrode . The transducer itself is composed of a network of carbon disc microelectrodes . This array of micrcelectrodes covers a sensing area of 5 x 5mm and is made up of some 1000-3000 electrodes. Individual disc microelectrodes measuring 15µm diameter, have a recessed geometry with hole depth of less than 10µm and centre-tocentre separation between 100 and 300µm . A novel three-stage fabrication process based on conventional thick-film printing techniques, vacuum polymerisation of a dielectric and a uv excimer laser photoablation process was used to pattern the disc array structure . This microfabricalion method has been evaluated on a laboratory scale and batch production . Amperometric performance and structural characteristics of the electrochemical sensor have been examined by chronoamperometry and electron microscopy . Variations in the sensor current response were studied in order to reduce the diffusion shielding characteristics of individual discs . An optimal microelectrode spacing was assigned to the sensor of 160µm giving more than one thousand discs per device . The printed sensor is currently under development for single-use field measurements of heavy metals using potentiometric stripping analysis .