Abstract
A PCR-free assay for rapid pathogen diagnosis was implemented on an integrated microfluidic system in this study. Vancomycin-conjugated magnetic beads were used to capture multiple strains of bacteria and nucleotide probes labeled gold nanoparticles were used to specify and detect a specific strain by hybridization-induced color change. The assay was entirely automated within an integrated microfluidic device that was composed of suction-type micropumps, microvalves, microchannels, and microchambers that fabricated by microfluidic technology. Multiple strains of bacteria could be captured simultaneously by vancomycin-conjugated magnetic beads, with capturing efficiency exceeding 80%. Subsequently, sensitive and strain-specific detection against target bacteria could be achieved by using nanogold labeled specific nucleotide probes. The limit of detection of 10 2 CFU bacteria was achieved. Importantly, nucleic acid amplification was not involved in the diagnostic procedures; the entire analytic process required only 25min. The developed platform may provide a promising tool for rapid diagnosis of bacterial infections. From the Clinical Editor: In this novel study, a PCR-free pathogen detection method is demonstrated. After vancomycin-conjugated magnetic beads captured bacteria, nucleotide probes-labeled gold nanoparticles were employed to specify and detect specific strains via hybridization-induced color change. Multiple strains of bacteria could be captured simultaneously with an efficiency exceeding 80%, enabling the detection of as low as 10 2 CFU of bacteria. © 2014 Elsevier Inc.