On biomolecules and semiconductors: Analytical studies of interface dynamics

The studies discussed here were undertaken to examine the use of III-V semiconducting materials as templates for biomolecules, to be applied in such technologies as Field-Effect Transistor (FET) and Light-emitting Diode (LED) biosensors. Materials application requires an informed analysis of interactions between chemical environments. Specific to surfaces, this means investigating the molecular interactions between the substrate and the bonding moieties. The analytical tools used to probe these interactions, and the changes that such communication causes on specific substrates are specifically discussed. Surface analysis tools included in this review are Atomic Force Microscopy (AFM), Nanoindentation, X-ray Photoelectron Spectroscopy (XPS), and Raman Microscopy. The interaction of biomolecules - deoxyribonucleic acid (DNA), proteins adhered to nanoparticles, and amino acids - on semiconductor surfaces is also examined. Proper investigation follows, as well, the methods of applying these biomolecular structures to the specified surfaces, through procedures such as solution phase transfer, as well as Dip-pen Nanolithography (DPN). The stretching and enzymatic cleavage of DNA, on silicon oxide surfaces, was studied to determine the recognition properties of dual-enzymatic systems on surfaces. Fundamental questions such as the interaction of functional groups with InAs(100) surfaces, the mechanical properties of protein modified systems, and the DPN application of biologically relevant linker molecules to InAs(100) surfaces were explored. These studies provide information applicable to the development of novel sensing platforms in the future