Target Recognition Initiated Self-Assembly-Based Signal Amplification Strategy for Sensitive and Colorimetric Staphylococcus aureus Detection and Diagnosis of Skin Infection.

Abstract

Staphylococcus aureus (S. aureus), as a Gram-positive bacterium, is commonly encountered in various infectious diseases, such as acute skin and soft tissue infections. Despite that many efforts have been made, sensitive and reliable quantitative determination of S. aureus remains a huge challenge. Here, we depict a novel colorimetric approach for sensitive and accurate detection by combining allosteric probe-based target recognition and chain extension-based dual signal recycling. The single-strand DNA (ssDNA) products generated by the chain extension process lead to the liberation of G-quadruplex sequences, which can fold into active DNAzyme under the assistance of hemin. The active DNAzyme can work as peroxidase mimics to catalyze the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS2-)-H2O2 system, causing the color change of the system. Eventually, the method exhibits a wide detection range from 103cfu/mL to 106cfu/mL. The limit of detection of the approach was determined 232cfu/mL. Considering the robust capability of the approach in S. aureus detection, we believe that it will be a potential alternative tool for biomedical research and clinical molecular diagnostics.