Capacitive Biosensors

✍ Scribed by Christine Berggren; Bjarni Bjarnason; Gillis Johansson

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 164 KB
• Volume: 13
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/1521-4109(200103)13:3<173::aid-elan173>3.0.co;2-b

✦ Synopsis

Work on a new type of biosensor, in which changes in the dielectric properties of an electrode surface are detected, started during the late 80s. The binding of an analyte to an immobilized af®nity element can be detected directly without the need for a label or an indicating reaction. The changes can be determined by measuring the electrical capacitance or impedance either by using interdigitated electrodes or more commonly by potentiostatic methods. Capacitive biosensors have been used for detection of antigens, antibodies, proteins, DNA fragments and heavy metal ions. Extremely low detection limits, down below 10 715 M, have been reached with plugged, self-assembled recognition layers.