TY - JOUR TI - Multifunctional biosensors using ZnO and its nanostructures DO - https://doi.org/doi:10.7282/T3WS8S6B PY - 2012 AB - In recent years, biosensors research has emerged as a major field in both academic institutes and industries with broad applications in drug discovery and development, clinical diagnostic tools, cancer and genetic research, agricultural and veterinary analysis, pollution and contamination monitoring, and food processing. ZnO is a wide band gap semiconductor with unique multifunctional material properties, which is particularly attractive for sensor technology. ZnO can be grown as thin films or as nanostructures with different morphologies on various substrates. Through proper doping, ZnO and its ternary MgxZn1-xO can be made transparent and conductive, piezoelectric, or ferromagnetic. ZnO-based sensors have demonstrated high sensitivity to various organic and inorganic gases and liquids. The biocompatibility of ZnO is demonstrated in detections of proteins, antibodies, and DNA through the proper surface functionalization. The control of the surface wettability of ZnO nanotips between super-hydrophilic and super-hydrophobic states are used to dramatically enhance the sensitivity of ZnO-based biosensors. The aim of this work is to create new paradigms in sensor technology through novel manipulation of nanometer-scale ZnO surfaces and structures, advancement of ZnO-based multi-modal sensing (e.g., acoustic, electrical, and optical). The new sensor technology is based on combination of accurate and high quality growth of multifunctional ZnO single crystal nanostructure arrays, organic and biomolecular functionalization of ZnO surfaces, and design and development of sensor platforms and devices. The key results of this research features the following sensors and their specific applications: (i) ZnO nanostructure-modified thin film bulk acoustic wave resonator (ZnOnano-TFBAR) for DNA detection, (ii) ZnO nanostructure-modified quartz crystal microbalance (ZnOnano-QCM) for dynamic and noninvasive monitoring of bovine aortic endothelial cells (BAEC), (iii) sensor-on-food packaging based on ZnO surface acoustic wave (SAW) sensor built on protein-coated flexible substrates, and (iv) ZnO thin film transistor immunosensor (ZnO-bioTFT) for detection of epithelial growth factor receptor (EGFR) proteins found in breast cancer cells. The new ZnO sensor technology presents great impact on the future classes of multi-modal and multifunctional biosensors and biochips for applications such as cell-based assay development, smart food packaging, and high throughput biosensor arrays that perform highly sensitive and selective biochemical detection. KW - Electrical and Computer Engineering KW - Biosensors KW - Nanostructured materials LA - eng ER -