CE chips fabricated by injection molding and polyethylene/thermoplastic elastomer film packaging methods

This study presents a new packaging method using a polyethylene/ thermoplastic elastomer (PE/TPE) film to seal an injection-molded CE chip made of either poly(methyl methacrylate) (PMMA) or polycarbonate (PC) materials. The packaging is performed at atmospheric pressure and at room temperature, which is a fast, easy, and reliable bonding method to form a sealed CE chip for chemical analysis and biomedical applications. The fabrication of PMMA and PC microfluidic channels is accomplished by using an injection-molding process, which could be mass-produced for commercial applications. In addition to micro-fluidic CE channels, 3-D reservoirs for storing biosamples, and CE buffers are also formed during this injection-molding process. With this approach, a commercial CE chip can be of low cost and disposable. Finally, the fimctionality of the mass-produced CE chip is demonstrated through its successfid separation of φX174 DNA/HaeIII markers. Experimental data show that the S/N for the CE chips using the PE/TPE film has a value of 5.34, when utilizing DNA markers with a concentration of 2 ng/μL and a CE buffer of 2% hydroxypropyl-methylcellulose (HPMC) in Tris-borate-EDTA (TBE) with 1% YO-PRO®-1 fluorescent dye. Thus, the detection limit of the developed chips is improved. Lastly, the developed CE chips are used for the separation and detection of PCR products. A mixture of an amplified antibiotic gene for Streptococcus pneumoniae and φX174 DNA/ HaeIII markers was successfully separated and detected by using the proposed CE chips. Experimental data show that these DNA samples were separated within 2 min. The study proposed a promising method for the development of mass-produced CE chips. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.