Polymer Based Biosensors for Pathogen Diagnostics

Over the past three decades researchers have witnessed an enormous amount of activity in the area of biosensors. The major processes involved in any biosensor system are analyte recognition, signal transduction, and readout. Due to their specificity, speed, portability, and low cost, biosensors offer exciting opportunities for numerous decentralized clinical applications – point of care systems. The ongoing trend in biomedicine is to go smaller. For almost a decade, the buzz word has been nano, and the analytical micro devices are now appearing in the clinic. The progress within microfluidic technologies has enabled miniaturization of biomedical systems and biosensors. The down-scaling has several advantages: refined control of fluidics, low sample consumption, applicability to point of care, and low cost. Point of care is an emerging field within medical diagnostics and disease monitoring, and eventually disease control. Employing specially designed micro systems, a patient can be monitored continuously at bed side, and save precious time on commuting between home, doctor and hospital. The technological advancements in the biosensor technology within recent years have accelerated the R&D in point of care devices. Cost benefit is always an important factor in development of novel medical devices. To reduce the expenses of biosensors, the use and cleanroom processing of noble metals should be kept at a minimum. Therefore, we predict a shift in the usage of gold and platinum to degradable polymer materials. This chapter will look further into the advantages and applications of all-polymer microfluidic devices for biomedical diagnostics and compare with traditional systems. In many biosensor applications, only one analyte is of interest, and preferentially it should be isolated from an inhomogeneous patient sample. Section 2 provides the reader with an overview of the different novel microfluidic separation techniques in polymeric devices. Conductive polymers are the focus of section 3. They have many excellent properties and in fact, they can compete with gold in many applications. The focus of section 4 is sensitivity and specificity of biosensors. High sensitivity and specificity is crucial and can be achieved by functionalization with different molecules. The section will primarily center around the use of aptamers which is favourable above antibodies. Different detection methods are applied in biosensors, some of the promising techniques will be summarized in section 5. Finally, section 6 gives an overview of the current status in biosensor development while focusing on ongoing research.