Dual-modal detection of antimicrobial susceptibility in pathogenic bacteria based on the high-throughput microfluidic platform

For pathogenic bacterial infectious diseases such as sepsis, accurate and rapid antimicrobial susceptibility testing (AST) plays an important role in improving antimicrobial screening and clinical outcomes. Traditional culturebased AST assays have the limitations of time-consuming, labor-intensive, expensive, and consuming reagents. In this work, a simple, fast, high-throughput microfluidic platform integrated with isolation, identification, and detection functions was designed for antibiotic susceptibility analysis in pathogenic bacteria. For the above purpose, MnO2@ZIF-90 nanoprobes with dual functions of nanozyme and fluorescence were prepared for visual eye or RGB analysis through a smartphone APP. More importantly, the redox activity of bacterial membrane in active pathogenic bacteria could decompose the MnO2 of MnO2@ZIF-90 nanoprobes and reduce the enzyme-like activity, which weakens the colorimetric signal of Timebox. Meanwhile, the ATP released from active pathogenic bacteria further triggered the breakdown of the inner ZIF-90 layer, generating a fluorescence signal. Therefore, a dual detection combining colorimetric and fluorescence was used to perform more accurate and reliable antibiotic susceptibility analysis of pathogenic bacteria. With the proposed microfluidic platform, a low detection of 10 CFU mL- 1 bacteria and fast AST results were achieved within 5 min. The clinical applicability of the platform was further demonstrated through the analysis of clinical samples. This work provides a low-cost, easy-tooperation, fast-response, and high-throughput platform for the AST assays in pathogenic bacterial infectious diseases such as sepsis.