Functionalization of Semiconductor Surfaces

CHAPTER 13

Immobilization of Biomolecules at Semiconductor Interfaces

ROBERT J. HAMERS

13.1 INTRODUCTION

Many emerging applications in biotechnology and biological/environmental sensing require surfaces that are highly selective and stable. The integration of biomolecules such as DNA and antibodies onto semiconductor surfaces provides several potential benefits. For example, semiconductors such as silicon are extremely pure and homogeneous, and can be used as highly reproducible substrates. Semiconductors such as silicon can be conveniently processed, etched, and manipulated using the tools developed for microchip fabrication, and translated toward biochips. In principle, it should be possible to take advantage of the unique properties that semiconducting materials can offer. Of these, one of the most important is the ability to amplify small changes in voltage or charge density and thereby convert biological information into measurable electrical signals in a highly parallel and low-cost manner. As one example, an inexpensive electronic voltmeter can read potential to four significant digits and costs less than $10. A current-generation microprocessor has over 2 billion transistors, each of which is a sensitive amplifier of current or voltage. If biological systems could be truly integrated with semiconductor-based materials, it could provide new opportunities for highly parallel biological detection. In the near term, bioelectronic devices are of interest for applications such ...