Label-Free Detection of DNA by Field-Effect Devices

DNA sensor and microarray technologies offer powerful tools for addressing various questions in biological and medical science. When these sensors and microarrays operate in a label-dependent manner, a low concentration of nucleic acid targets can be detected with excellent sensitivity. Nonetheless, label-free detection techniques eliminate labeling steps and therefore may allow rapid and low-cost assays. Field-effect devices provide a promising label-free approach for the high-throughput real-time monitoring of nucleic acids. This paper reviews major concepts and recent progress on the application of field-effect devices for DNA sensing. First, device architectures are described in terms of what events are detectable, how sensor systems are constructed, and how capture probes are immobilized on a gate surface. Hybridization detection, the limit of charge detection, and ways to overcome this limitation are also discussed.