Amperometric Detection of Carbohydrates with a Portable Silicone/Quartz Capillary Microchip by Designed Fracture Sampling

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• 作者：Chun Zhai ; Chen Li ; Wei Qiang ; Jianping Lei ; Xiaodong Yu ; Huangxian Ju
• 刊名：Analytical Chemistry
• 出版年：2007
• 出版时间：December 15, 2007
• 年：2007
• 卷：79
• 期：24
• 页码：9427 - 9432
• 全文大小：316K
• 年卷期：v.79,no.24(December 15, 2007)
• ISSN：1520-6882

文摘

A silicone/quartz capillary microchip (SQCM) coupledwith an ultranarrow sampling fracture was for the firsttime constructed without any micromachining. The SQCMcould be used for direct determination of carbohydratesat a detection potential of +0.8 V (vs Ag/AgCl) with acopper microdisk electrode. The ultranarrow samplingfracture could be conveniently formed on a quartz capillary, which was fixed by a frame of poly(dimethylsiloxane)(PDMS). The designed fracture sampling suppressed theleakage of sample, thus simplifying the power supply.Furthermore, it thinned the sample plug for enhancingthe resolution. The quartz capillary reduced the adsorption of analytes on the separation channel wall comparedwith a general PDMS microchip, thus enhanced theseparation efficiency up to 239 000 plates/m for carbohydrates. This proposed system could satisfactorily separate eight carbohydrates within 180 s with good reproducibility and sensitively detect them in the linear rangesfrom 1 M to 0.5 mM for trehalose and sucrose, 2.5 Mto 0.5 mM for lactose, galactose, glucose, and mannose,and 2.5 M to 1.5 mM for fructose and xylose with thedetection limit down to 90 amol. The designed microchipwas successfully applied to detect carbohydrates in apractical acacia honey sample.