Bioaffinity sensing using biologically functionalized conductingpolymer nanowire

Recent advances in electronic detection based on nanowires (NWs) and nanotubes (NTs) has revolutionized our ability to pro-vide label-free and real-time, yet sensitive and selective detection of a wide range of chemical and biological species using the NW or NT as the gate of a planar field effect transistor (FET).1 Unlike two-dimensional FETs, one-dimensional nanowires avoid the reduc-tion in conductance changes caused by lateral current shunting to the point that even single-molecule detection is possible. The selec-tivity of the nanosensors can be further enhanced by modification with specific bioreceptors such as antibodies. Examples of silicon nanowire (SiNWs) and carbon nanotubes (CNT) functionalized with biotin and human autoantigen (U1A), respectively, for label-free, sensitive, and real-time detection have been reported.1,2 The suggested mechanism for the resulting high sensitivity, potentially to single molecule, is the extremely sensitive modulation of th