A Lateral Flow Test for <i>Staphylococcus aureus</i> in Nasal Mucus Using a New DNAzyme as the Recognition Element
M. Monsur Ali, Ryan Silva, Dawn White, Saeed Mohammadi, Yingfu Li, Alfredo Capretta, John D. Brennan
Abstract
Abstract Detection of pathogenic bacteria in complex biological matrices remains a major challenge. Herein, we report the selection and optimization of a new DNAzyme for Staphylococcus aureus (SA) and the use of the DNAzyme to develop a simple lateral flow device (LFD) for detection of SA in nasal mucus. The DNAzyme was generated by in vitro selection using a crude extra/intracellular mixture derived from SA, which could be used directly for simple solution or paper‐based fluorescence assays for SA. The DNAzyme was further modified to produce a DNA cleavage fragment that acted as a bridging element to bind DNA‐modified gold nanoparticles to the test line of a LFD, producing a simple colorimetric dipstick test. The LFD was evaluated with nasal mucus samples spiked with SA, and demonstrated that SA detection was possible in minutes with minimal sample processing.