A microfluidic system for rapid bacterial pathogen detection

We previously demonstrated application of a MEMS electrochemical biosensor to detect pathogenic bacteria in urine. Using custom-designed DNA oligonucleotide probes specific for bacterial 16S rRNA, species-specific detection was achieved within 45 minutes. However, the urine sample preparation protocol is still a labor-intensive 7 to 10 step process. This paper outlines our initial efforts to develop PDMS-based pump and mixer designs compatible with our existing electrochemical biosensor. The eventual goal is to use these preliminary designs and numerical and experimental test results from various microfluidic components in PDMS in order to build an integrated lab-on-a-chip for rapid bacterial pathogen detection. Preliminary active mixing tests show at a four-fold improvement in the resulting electrochemical signal amplitude, when compared to flow through the microfluidic structure without mixing, as well as when compared to manual mixing.