title: Integrated optical-fiber capillary electrophoresis microchips with novel spin-on-glass surface modification.
abstract: This paper presents a novel micro-capillary electrophoresis (CE) chip with embedded optical fibers for the on-line detection of DNA samples. The optical fibers are pre-etched and then inserted directly into fiber channels incorporated within low-cost soda-lime glass substrates. The embedded optical fibers are precisely aligned with the microfluidic channels such that the induced fluorescence signals from labeled bio-samples can be detected. This arrangement avoids the requirement for delicate optical alignment procedures and equipment. Surface modification of the CE channels is accomplished by means of a simple and reliable organic-based spin-on-glass (SOG) method. The zeta potential distribution and the corresponding electroosmotic mobility of the fluid are simulated numerically for the modified and non-modified channel surfaces, and then both sets of results are verified experimentally. The present results indicate that the value of the zeta potential for a surface with an SOG coating is 19.3 times smaller than that of an untreated surface. A phiX-174 DNA marker fluid is used to evaluate the injection and separation performance of the developed micro-CE device. Furthermore, the long-term stability of the SOG-coated surface is also investigated. The experimental data reveal that the microchip device is capable of providing highly efficient separations of bio-molecules, and that the SOG layer retains its low zeta potential characteristics for at least 45 days. The present results confirm the effectiveness of the proposed micro-CE chip in performing the on-line detection of DNA samples, and indicate that the SOG process represents a simple and reliable solution for the surface modification of glass-based microchannels.
authors.affiliation: Department of Mechanical and Electro-mechanical Engineering, National Sun Yat-Sen University, Taiwan, ROC.
authors.forename: Che-Hsin
authors.initials: CH
authors.lastname: Lin
authors.forename: Gwo-Bin
authors.initials: GB
authors.lastname: Lee
authors.forename: Lung-Ming
authors.initials: LM
authors.lastname: Fu
authors.forename: Shu-Hui
authors.initials: SH
authors.lastname: Chen
mesh_terms: D001435:Bacteriophages / Q000235:genetics; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D045424:Complex Mixtures / Q000032:analysis / Q000737:chemistry; D004279:DNA, Viral / Q000032:analysis* / Q000737:chemistry; D004586:Electrophoresis / Q000295:instrumentation* / Q000379:methods; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods; D046209:Electrophoresis, Microchip / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation* / Q000379:methods; D005898:Glass / Q000737:chemistry; D008832:Microchemistry / Q000295:instrumentation* / Q000379:methods; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods; D055100:Optical Fibers; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers
chemical_list: D020099:Coated Materials, Biocompatible; D045424:Complex Mixtures; D004279:DNA, Viral