1.8. Future Prospects

Data Processing and Pattern Recognition. If we compare the present biosensors with the natural ones (of, for example, the nose or the eye), they are very crude and simplistic. The recognition molecules in the 'natural sensors' are not necessarily highly specific but the signal transduction via the biomolecules is sophisticated. The specificity often comes from processing of the data collected and recognizing the pattern via a continuous learning process. This mode of operation using the data collected from multiple biosensors is expected to be exploited in the future because the ever increasing capability of microprocessors will provide fast computation.

Micro Instrument. As shown in Fig 1.14, the third generation biosensors have built-in signal processing circuitry. When such sensors are combined with the micro scale valves and actuators currently under development (utilizing micromachining technology), a whole analytical instrument can be built on a silicon wafer. Such an instrument can be mass produced and used in a variety of applications including homes, hospitals, automobiles, toxic dump sites, etc.

Molecular Electronics. The effort to continuously increase the density of electronic components to obtain ever smaller 'packages' will be limited eventually, not by the microlithographic technique employed but by the minimum size allowable for a transistor (note that 'transistor' is the building block of microprocessors and memory chips). Many biological molecules are able to synthesize complex self-organizing molecules with apparently just the required electronic properties. This suggests that the solution to this problem may be found in replacing silicon with biomolecular components. This idea has led to the proposition of many molecular electronic systems. In the past, materials and processing methods developed for microelectronic applications have been exploited in sensor developments. Therefore, any future developments in molecular electronics are expected to be imported into biosensor technology.

Multi-Disciplinary Nature. The arena of expertise required for biosensor development can be sustained by collaboration from many areas of academia and industry (as illustrated in Fig. 1.15). The resulting output of this collaboration is likely in many cases to be a slow process, but is probably the only realistic route to successful future advances.