Label-free DNA biosensors with field-effect devices

In the recent decades, the detection of specific deoxyribonucleic acid (DNA) molecules has attracted more and more attention due to the fast increasing demand of DNA analysis, which plays very important roles in a wide range of applications such as molecular diagnostics, gene analysis, and environmental monitoring. Field-effect devices (FEDs) open up an exciting realm for the development of label-free DNA biosensors due to the fast advances in the microfabrication process. FED-based DNA biosensors have achieved significant advances and shown promising prospects and potential applications in many fields. In this chapter, the basic mechanisms and recent progress in the development of FED-based DNA biosensors will be reviewed in detail. For the first, the basic principle of FED-based DNA biosensors will be introduced, which will focus on the signal generation mechanisms of DNA hybridization and the signal transduction and readout by FEDs. In the second part, the design considerations of FED-based DNA biosensors will be discussed, which include the coupling of probe ssDNA FEDs, measurement solutions, and sensor system. Finally, the applications of FED-based DNA biosensors in two typical and important fields will be summarized, which are label-free DNA assays and detection of single nucleotide polymorphisms (SNPs). The development trends and the current main challenges of FED-based DNA biosensors will be provided and discussed in the final section.