Nucleic acid biosensors

There is an ever increasing need to expand the realm of diagnostic capabilities. The need for accurate and reliable biological detection methods is crucial for genetic analysis, drug discovery, the monitoring of bacteria and viruses in food and water samples, as well as monitoring the environment for biothreat reagents. In the realm of diagnostics, molecular biology first expanded to include semiconductor manufacturing technology in the creation of a DNA biosensor array. Currently, biosensor arrays are being developed to utilizing complex sensors for the detection of multiple types of analytes. Important to the future applications for biosensor technology is the development of miniaturized systems that utilize sophisticated sensors. We have explored the use of platforms that offer a three-dimensional volume element, as well as sophisticated nucleic acid sensors. A flow cell based microsphere platform (electronic tongue), and a novel hydrogel platform based on shape recognition elements (MUFFINS), have been combined with nucleic acid sensors (ssDNA and aptamers) and fluorescence microscopy to create biosensors for the detection of DNA and proteins. As a step towards fulfilling the goal of developing a second generation of sophisticated sensors, signaling aptamers were engineered. Signaling aptamers are nucleic acid ligands (aptamers) that are capable of displaying changes in fluorescent signal upon binding to their cognate analyte. In addition, “affinity” microspheres were developed for the direct synthesis of microsphere bound nucleic acid sensors.