Analysis of dopamine and tyrosinase activity on ion-sensitive field-effect transistor (ISFET) devices

作者：Freeman Ronit; Elbaz Johann; Gill Ron; Zayats Maya; Willner Itamar^*

来源：Chemistry - A European Journal, 2007, 13(26): 7288-7293.

DOI：10.1002/chem.200700734

• biosensors
• enzymes
• ion-sensitive field-effect transistors
• monolayers
• tyrosinase

Dopamine (1) and tyrosinase (TR) activities were analyzed by using chemically modified ion-sensitive field-effect transistor (ISFET) devices. In one configuration, a phenylboronic acid functionalized ISFET was used to analyze 1 or TR. The formation of the boronate-1 complex on the surface of the gate altered the electrical potential associated with the gate, and thus enabled 1 to be analyzed with a detection limit of 7 x 10(-5) M. Similarly, the TR-induced formation of 1, and its association with the boronic acid ligand al- lowed a quantitative assay of TR to be performed. In another configuration, the surface of the ISFET gate was modified with tyramine or 1 to form functional surfaces for analyzing TR activities. The TR-induced oxidation of the tyramine- or 1-functionalized ISFETs resulted in the formation of the redox-active dopaquinone units. The control of the gate potential by the redox-active dopaquinone units allowed a quantitative assay of TR to be performed. The dopaquinone-functionalized ISFETs could be regenerated to give the 1-modified sensing devices by treatment with ascorbic acid.

• 出版日期2007