Development of a sol-gel enzyme inhibition-based amperometric biosensor for cyanide

✍ Scribed by Tae-Myung Park; Emmanuel I. Iwuoha; Malcolm R. Smyth

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 397 KB
• Volume: 9
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/elan.1140091416

✦ Synopsis

An amperometric sol-gel-based enzyme inhibition electrode for the detection of low levels of cyanide was constructed by immobilizing horseradish peroxidase (HRP) and an osmium redox polymer ([Os(bpy)2(PVP)loC1]Cl; abbreviated 0s-polymer) as mediator. Upon addition of hydrogen peroxide to the solution, a bioelectrocatalytic reduction wave was observed, which was diffusion controlled. This reduction current is subsequently inhibited by cyanide. The steady-state hydrogen peroxide catalytic reduction current reached a plateau at 150 mV (vs. Ag/ AgCI) and cyanide could be determined amperometrically with good sensitivity at OmV (vs. Ag/AgCI). The concentration range of linear response, apparent inhibition constant (K;), and detection limit were 0.004-0.04mM, 0.0637 mM, and 0.5 pM, respectively. Sodium azide, potassium thiocyanide and thiourea were all found not to interfere at this potential. The biosensor was found to be stable for over 1 week on storage at room temperature.