Detection schemes for determining the presence of bacteria, viruses, and toxins are important for diagnostic testing and viral outbreak control. Polymerase chain reaction (PCR)-based detection schemes are commonly used, but tend to result in false positives and negatives. Alternatively, color-changing diagnostic sensing methods, made possible by advances in nanoparticle technology, make more simple point-of-use testing feasible.
Most nanoparticle-based color changing detection schemes rely on nanoparticle aggregation or disassembly. Thus, they show qualitative color change but struggle to give quantitative results, are not applicable to all sample types, and still require complex equipment and procedures.
Dr. Peng Zhang and his team have identified nanoparticles capable of catalyzing chemical reactions which result in detectable color change. Based on this discovery, they have developed a novel colorimetric detection scheme that allows for accurate quantitative results. Their data indicates great potential for detecting bacteria and DNA, and can also be adapted to detect viruses, toxins, and pollutants.