Nanowire biosensors for label-free, real-time, ultrasensitive protein detection.

Sensitive and quantitative analysis of proteins is central to disease diagnosis, drug screening, and proteomic studies. Among recent research advances exploiting new nanomaterials for biomolecule analysis, silicon nanowires (SiNWs), which are configured as field-effect transistors (FETs), have emerged as one of the most promising and powerful platforms for label-free, real-time, and highly sensitive electrical detection of proteins as well as many other biological species. Here, we describe a detailed protocol for realizing SiNW biosensors for protein detection that includes SiNW synthesis, FET device fabrication, surface receptor functionalization, and electrical sensing measurements. Moreover, incorporating both p-type and n-type SiNWs in the same sensor array provides a unique means of internal control for sensing signal verification.