Influence of surface-active compounds on the response and sensitivity of cholinesterase biosensors for inhibitor determination

• Published in: Analyst (London) Vol. 121; no. 12; pp. 1911 - 1915
• Main Authors: Evtugyn, G A, Budnikov, H C, Nikolskaya, E B
• Format: Journal Article
• Language: English
• Published: England 01.12.1996
• Subjects: Biosensing Techniques; Cholinesterase Inhibitors - analysis; Cholinesterases - chemistry; Enzymes, Immobilized; Potentiometry; Surface-Active Agents - chemistry
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/AN9962101911

The influence of non-ionogenic surfactants, i.e., Tween-20, Triton X-100 and PEG-10,000, on the response of cholinesterase-based potentiometric biosensors and their sensitivity towards reversible and irreversible inhibitors were investigated. Acetyl- and butyrylcholinesterases were immobilized on nylon, cellulose nitrate films and tracing paper and were introduced into an assembly of potentiometric biosensors. The effect of surface-active compounds depends on the hydrophilic properties and porosity of the enzyme support material and the inhibition mechanism. In the range 0.002-0.3% m/v the surfactants show a reversible inhibiting effect on biosensor response. At lower concentrations (down to 10(-4)% m/v) the surfactants alter the analytical characteristics of reversible and irreversible inhibitor determination. The use of surface-active additives improves the biosensor selectivity in multi-component media.