Development and Electrochemical Investigations of an EIS- (Electrolyte-Insulator-Semiconductor) based Biosensor for Cyanide Detection

Monika Turek, Lothar Ketterer, Melanie Claßen, Heinz Berndt, Gereon Elbers, Peter Krüger, Michael Keusgen, Michael Schöning
2007 Sensors  
A cyanide biosensor based on a pH-sensitive p-doped electrolyte-insulatorsemiconductor (EIS) structure with an immobilised enzyme (cyanidase) is realised at the laboratory scale. The immobilisation of the cyanidase is performed in two distinct steps: first, the covalent coupling of cyanidase to an N-hydroxysuccinimide-(NHS) activated Sepharose TM gel and then, the physical entrapment of NHS-activated Sepharose TM with the immobilised cyanidase in a dialysis membrane onto the EIS structure. The
more » ... EIS structure. The immobilisation of the cyanidase to the NHS-activated Sepharose TM is studied by means of gel electrophoresis measurements and investigations using an ammonia-(NH 3 ) selective electrode. For the electrochemical characterisation of the cyanide biosensor, capacitance/voltage and constant capacitance measurements, respectively, have been carried out. A differential measurement procedure is presented to evaluate the cyanide concentration-dependent biosensor signals.
doi:10.3390/s7081415 fatcat:ejthynzx7neprjjhbbrskbcsum