A method for highly sensitive detection of silver nanoparticles using a micro-resonator and DNA assisted conjugation

Silver nanoparticles (AgNPs) have garnered significant interest owing to their unique properties and therefore, AgNPs have widespread application. However, there have been recent reports about the risks posed by AgNPs to human health and a highly sensitive tool for detecting AgNPs in aquatic environments is required to prevent their harmful effects on humans. In this article, we propose highly sensitive detection of AgNPs using a micro-resonator and the DNA assisted conjugation method. The detection method is based on the resonance frequency shift of the resonator upon adsorption of conjugated AgNPs. We have used the DNA assisted AgNPs conjugation method to amplify the mass of the detection target. By using this micro-resonator in combination with the conjugation method, we were able to achieve highly sensitive and selective detection of AgNPs, with detection limits of approximately 10 ng/mL in distilled water, which is at least 10 times more sensitive than that described in previous reports. Further, we also performed detection in real drinking water samples.