An Au nanoparticle/bisbipyridinium cyclophane-functionalized ion sensitivefield-effect transistor for the sensing of adrenaline

A film consisting of polyethyleneimine (PEI), An nanoparticles (12 +/- 1 nm ) and coadsorbed cyclobis(paraquat-p-phenylene) (1) was assembled as a sens ing interface on the Al2O3 insulating layer of an ion-sensitive field-effec t transistor (ISFET). Adrenaline (2) was sensed by the functionalized ISFET with a detection limit of 1 x 10(-6) M. The sensing ability of the nanostr uctured device for the analysis of adrenaline originates from the preconcen tration of the analyte in the cyclophane by pi-pi donor-acceptor interactio ns. Analysis of adrenaline is accomplished by the measurement of the source -drain current, I-sd, or by the gate-source voltage, V-gs. The sensing devi ce is reusable (at least 100 cycles) and exhibits high stability.