Selective functionalization on ultra-thin body FETs

A new method of selective functionalization of ultra-thin body field-effect transistors (UTBFETs) is reported for biosensor applications. A polymer film, Polymethylmethacrylate (PMMA), is used as blocking layer and is ablated electrically at the specific region on UTBFETs by localized joule heating. The exposed site was then functionalized with a chemical linker molecule, N-(2-Aminoethyl)- 3-aminopropyl-trimethoxysilane (AEAPTMS), while the surrounding area is still protected by the chemically inert polymer layer. As demonstration, both gold nanoparticles (AuNPs) and fluorescein isothiocyanate (FITC) molecules are selectively bound onto the linker molecules subsequently on the surface of exposed binding sites of UTBFETs.