An integrated microfluidic device utilizing vancomycin conjugated magnetic beads and nanogold-labeled specific nucleotide probes for rapid pathogen diagnosis.
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.


BACKGROUND
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.
Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan. Electronic address: biowang2007@gmail.com.
Chih-Hung
CH
Wang
Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan. Electronic address: jerry780620@gmail.com.
Chia-Jung
CJ
Chang
Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University, Tainan, Taiwan. Electronic address: jjwu@mail.ncku.edu.tw.
Jiunn-Jong
JJ
Wu
Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan; Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu, Taiwan; Institute of Nano Engineering and Microsystems, National Tsing Hua University, Hsinchu, Taiwan. Electronic address: gwobin@pme.nthu.edu.tw.
Gwo-Bin
GB
Lee
D001424:Bacterial Infections / Q000175:diagnosis* / Q000235:genetics; D015373:Bacterial Typing Techniques / Q000295:instrumentation / Q000379:methods; D015342:DNA Probes / Q000737:chemistry* / Q000235:genetics; D006046:Gold / Q000737:chemistry*; D006090:Gram-Negative Bacteria / Q000145:classification / Q000235:genetics*; D006094:Gram-Positive Bacteria / Q000145:classification / Q000235:genetics*; D053768:Metal Nanoparticles / Q000737:chemistry*; D046210:Microfluidic Analytical Techniques
D015342:DNA Probes; D006046:Gold
Bacteria; Microfluidic; Nanogold; Vancomycin