Amperometrische Biosensoren zur Bestimmung von Cholin und Acetylcholin

Summary Amperometric biosensors for the determination of choline and acetylcholine were constructed by coupling immobilized choline oxidase or choline oxidase and acetylcholinesterase membrane with an electrode. H₂O₂ which results from the oxidase reaction is anodically monitored. The sensors' response is linear in the concentration range of 1 to 300 mol/l choline and 1 to at least 660 mol/l acetylcholine. The sample frequency is 60 h^–1 with an imprecision of less than 2% for both choline and acetylcholine. The longtime-stability of the sensors was tested to be more than 22 days. The influence of the reversible inhibitor NaF on the bienzyme-electrode response was investigated.     

Molekül‐Detektive. Biosensoren

Biosensors are analytical devices incorporating biological material (receptor) intimately associated with or integrated within a physicochemical transducer. Advantages are the high selectivity for analyte detection. Examples given comprise the very successful commercial blood glucose biosensors made for the self‐control by the diabetic patients. Other biosensors are part of an analytic system, including the sensor chips of surface plasmon resonance or interferometry based devices, piezoelectric or reflectometric sensors capable of direct measurement of mass changes, and thermometric and other reagentless sensors. The development of nanotubes‐based devices allows for significant enhancment of the signal‐tonoise ratio of the biosensors. A milestone on the way towards miniaturization and parallelization of biosensors is the recently developed and prize‐winning electronic DNA chip.