Nanofabrication of Single Electron Transistors and Evaluation of Miniature Biosensors
This thesis deals with miniaturization in two different fields: electronics and biosensing.
The first part deals with fabrication and measurements of two nanoscale structures - a self-assembled single electron transistor and a (potential) single junction device. The active part of these devices were less than 10 nm, which was achieved by a combination of standard lithographic techniques such as photo-lithography and electron beam lithography, with new approaches; angle evaporation, electro-deposition and chemical synthesis of nano-scale objects. In these devices Coulomb blockade was observed at room temperature and Coulomb staircase and gate effects at 4.2 K.
The second part explores two biosensing concepts for, real time monitoring of bioevents at a solid-liquid interface. The two physical principles employed were high frequency forward ac transmission and nanoparticle plasmon resonance. The forward ac transmission sensing approach measures changes in the forward ac transmission at the interface, caused by some biological event. The specific example demonstrated here is lipid bi-layer formation from vesicles and the enzymatic action of phospholipase A2 on the bi-layer. The nanoparticle plasmon resonance is demonstrated for biomolecular adsorption and binding kinetics. Both techniques are compatible with chip-based miniaturization.
single electron tunneling
surface plasmon resonance