A New Approach toward the Realization of Specific and Label-Free Biological Sensing Based on Field-Effect Devices

Specific and label-free detection of biological interactions is paramount to a plethora of technological applications ranging from home-care diagnostics to smart agriculture and home security. The biologically-modified field-effect transistor (BioFET) is a promising sensing platform due to its inherent signal amplification, low power, and miniaturization. In the following a low-cost meta-nano-channel BioFET (MNC BioFET) is reported that provides means to electrostatically control the size, shape, and location of the conducting channel such as to enhance the coupling between the locally-occurring electrostatics of the biological interactions and the electrodynamics of the underlying conducting channel. Moreover, it provides means to electrostatically control the Debye screening length at the sensing area to increase the readout signal. The MNC BioFET is fabricated in a large-scale silicon chip foundry that ensures robustness and stability, optimal noise levels and signal amplification, repeatability, and ultimate miniaturization with the potential for high-end multiplexing in ultra-small samples. In the current study, a specific and label-free sensing of prostate specific antigen with the MNC BioFET is demonstrated, and show the dependency of the sensor signal on the channel configuration. Finally, an order of magnitude enhancement in readout signal is demonstrated by the electrostatic control of the screening length at the sensing area.