Nanostructured ZnO Thin Film Transistor Biosensor with High Sensitivity and Selectivity

Sensitive and selective detection of EGFR in serum. (a) Drain current vs. gate bias plot. (b) Sensitivity plot of the device for pure EGFR and EGFR in serum detection. (c) Sensor schematic.


Invention Summary:

Various semiconductor devices have been developed for use as biosensors including Ion Sensitive Field Effect Transistors (ISFETs), Organic Field Effect Transistors (OFETs), and nanowire-based FET sensors. However, all of these FET-based devices have drawbacks ranging from high bias voltage, low mobility, low output current, low sensitivity, to complex fabrication processes. Zinc Oxide (ZnO), on the other hand, have been increasingly used as wide band gap semiconductor oxide because of its multifunctional properties. As ZnO and its nanostructures are biocompatible, ZnO–based sensors have been developed to detect biomolecules such as proteins and nucleic acids.

Researchers at Rutgers University have developed a novel biosensor built on the ZnO thin film transistor (TFT) technology with integrated ZnO nanostructures. The surface of the ZnO TFT is biofuntionalized with a bio-functional linker layer having affinities for specific biomarkers (for example, m-abs-EGFR to EGFR-protein initial demonstration). Detection of the presence of a biomarker can be achieved by channel carrier modulation via pseudo double-gating field effect caused by the antibody-mediated capturing of the biomarker on the surface of the biosensor. The presence of ZnO nanostructures facilitates the control of the morphology and wettability, as well as biochemical functionalization of the sensing surface, which ultimately results in enhanced sensitivity and selectivity (10 fM achieved for EGFR) with significant reduction in analyte intake. The developed biosensor could be used commercially as a low cost, disposable, research/diagnostic device. Further development of the sensor will include (i) doped -nanostructure-modified sensing surface to enhance biofunctionalization; (ii) new linker layers to enhance the selectivity; (iii) an arrayed and reconfigurable device architecture for high throughput biochemical sensing and drug screening. Depending on the functionalized groups attached to the surface ZnO nanostructures, this technology could also be used for other specific biosensing and testing applications.

Market Application:

The technology can be integrated with microfluidics and signal processing circuitry to form Sensor-on-a-Chip suitable for diagnostic and research in drug development, assay technology and cancer pharmacology.

Advantages:

  • High sensitivity & selectivity at low cost
  • Multimodal operation
  • Rapid and high throughput sensing

Intellectual Property & Development Status:

US patent 9,064,965. Available for licensing and/or research collaboration.