Silicon nanowire field-effect-transistor based biosensors: From sensitive to ultra-sensitive

• Introducing the sensing mechanism of SiNW-FET biosensor.
• Summarizing the various approaches for receptor immobilization on SiNW-FET.
• Discussing various strategies for improving the sensitivity of SiNW-FET.
• Reviewing the challenges remained on the clinical applications.

Silicon nanowire field effect transistors (SiNW-FETs) have shown great promise as biosensors in highly sensitive, selective, real-time and label-free measurements. While applications of SiNW-FETs for detection of biological species have been described in several publications, less attention has been devoted to summarize the conjugating methods involved in linking organic bio-receptors with the inorganic transducer and the strategies of improving the sensitivity of devices. This article attempts to focus on summarizing the various organic immobilization approaches and discussing various sensitivity improving strategies, that include (I) reducing non-specific binding, (II) alignment of the probes, (III) enhancing signals by charge reporter, (IV) novel architecture structures, and (V) sensing in the sub-threshold regime.