Korpan_2002_Bioelectrochemistry_55_9

For the design of a biosensor sensitive to steroidal glycoalkaloids pH-Sensitive Field Effect Transistors as transducers and immobilised butyrylcholinesterase as a biorecognition element have been used The total potato glycoalcaloids can be measured by this biosensor in the concentration range 0.5-100 mgr;M with detection limits of 0.5 mgr;M for alpha-chaconine and of 2.0 mgr;M for alpha-solanine and solanidine respectively The responses of the developed biosensors were reproducible with a relative standard deviation of about 1.5 and 5 for intra and inter-sensor responses both cases n=10 for an alkaloid concentration of 5 mgr;M respectively Moreover due to the reversibility of the enzyme inhibition the same sensor chip with immobilised butyrylcholinesterase can be used several times for at least 100 measurements after a simple washing by a buffer solution and can be stored at 4 degrees C for at least 3 months without any significant loss of the enzymatic activity