A simple and rapid colorimetric detection of relied on the distance-dependent optical properties of silver nanoparticles.

The quick and accurate diagnosis of pathogens has appeared as a pressing issue in clinical diagnostics, environmental monitoring, and food safety. The available assays are suffering from limited capacities in simple, fast, low-cost, and on-site detection to increase prevention and proper treatment. Herein, we address these challenges by developing a simple, speedy, affordable, and ultrasensitive nanoplasmonic biosensor for colorimetric detection of cDNA from RNA relying on the distance-dependent optical features of silver nanostructures for the measurement of color variations and spectral shifts owing to the plasmon coupling generated by the cross-linking accumulation of AgNPs.