An Aptamer-Based Sensor For Small Molecules

Sensing small molecules in unprocessed aqueous solutions, such as blood and simple soil extracts, would be a boon for point-of-care medical diagnostics and environmental monitoring in the field. So far, however, such systems have been developed for only a few specialized targets. Now, scientists at the University of California, Santa Barbara, have developed a new microfluidic, electrochemical, aptamer-based sensor that has the potential to monitor many different targets (J. Am. Chem. Soc., DOI: 10.1021/ja806531z). The sensor, developed by H. T. Soh and colleagues, integrates short strands of DNA that fold when exposed to a specific small molecule, thereby generating an electrical signal in the presence of the analyte. Soh's team created a sensor for cocaine and found that it took only a minute for the device to detect the narcotic in undiluted blood at micromolar concentration. This approach "may lay the groundwork for the real-time, point-of-care detection of a wide variety of molecular targets," the authors note.