Kim, JaemyungRim, You SeungChen, HuajunCao, HuanNakatsuka, NakoHinton, HannahZhao, ChuanzhenAndrews Anne M.Yang, YangWeiss, Paul2024-01-232024-01-232024-01-232015-03-2310.1021/acsnano.5b01211https://infoscience.epfl.ch/handle/20.500.14299/203128We demonstrate straightforward fabrication of highly sensitive biosensor arrays based on field-effect transistors, using an efficient high-throughput, large-area patterning process. Chemical lift-off lithography is used to construct field-effect transistor arrays with high spatial precision suitable for the fabrication of both micrometer- and nanometer-scale devices. Sol–gel processing is used to deposit ultrathin (∼4 nm) In2O3 films as semiconducting channel layers. The aqueous sol–gel process produces uniform In2O3 coatings with thicknesses of a few nanometers over large areas through simple spin-coating, and only low-temperature thermal annealing of the coatings is required. The ultrathin In2O3 enables construction of highly sensitive and selective biosensors through immobilization of specific aptamers to the channel surface; the ability to detect subnanomolar concentrations of dopamine is demonstrated.BiosensorChemical lift-off lithographyDNA aptamerDopamineField-effect transistorNeurotransmittertext::journal::journal article::research article