Point of need analyte detection using dsDNA templated fluorescent copper nanoparticles

Abstract

The detection of various types of pollutants, toxins, and adulterants that are detrimental to the environment and human health is essential for monitoring air, water, soil, and food quality. Technologies that enable the detection and quantification of analytes at the point-of-need can enable decision makers to take timely and effective actions to minimize damage and avert widespread crisis. In recent years, different types of nanomaterials in conjunction with various sensing technologies have led to the creation of novel and highly sensitive analyte detection assays. Of these nanomaterials, fluorescent copper nanoparticles templated by dsDNA have garnered considerable research interest due to their low-cost, wide availability, and relative ease of synthesis. The analyte detection assays utilizing dsDNA-templated copper nanoparticles have the potential to be deployed in point-of-need settings as they do not involve complex procedures and generate results within a short period of time. However, there are a few challenges inherent to copper nanoparticle-based assays that prevent their use outside laboratory settings. The detection of the weak fluorescence emission from the nanoparticles requires the use of highly sensitive and expensive detectors. Further, the fluorescence emission intensity from the nanoparticles varies with time, making the technique sensitive to the time of measurement. Introducing specificity into analyte detection assays using these nanoparticles also remains a challenge. This thesis proposes techniques to address these challenges to facilitate the adaptation of copper nanoparticle-based fluorescence assays for point-of-need applications. Additionally, the thesis proposes three new analyte detection assays. Firstly, a chemical technique to improve the fluorescence properties of dsDNA-templated copper nanoparticles is proposed...