超支化聚胺-酯改性聚二甲基硅氧烷微流控芯片的紫外检测应用

Surface Modification of Poly(dimethylsiloxane) Microfluidic Chips by Hyperbranched Polyaminoester for Ultraviolet Detection

采用超支化聚胺-酯对经过氧气氛处理的PDMS微流控芯片表面进行改性。成功地将超支化聚胺-酯涂覆到PDMS表面,使其表面的接触角由108°±1°降到32°±2°,改善了其亲水性;改性过后通道内的电渗流得到了有效抑制,远低于未改性通道内的电渗流。同时,将芯片通过专门设计的通道与毛细管连接在一起,在紫外检测波长214 nm,分离电压5 kV,pH 4.5,电动进样条件下,成功实现了对腺苷和L-色氨酸的紫外检测分离。改性后的芯片对检测物质的分离度可以达到2.01,信号重现性RSD(n=4)分别为2.75%(腺苷)和1.54%(L-色氨酸)。本方法为改性PDMS微流控芯片提供了一种新方法。

Hyperbranched polyaminoesters（HPAE） were used for poly（dimethylsiloxane）（PDMS） microfluidic chips modification.The microdevices were treated in oxygen atmosphere before modification.The contact angles of PDMS were lowered from 108°±1° to 32°±2° in this method.The hydrophilcity of PDMS was improved.The electroosmotic flow（EOF） in the modified microchannel was lower than that in the unmodified microchannel.The EOF in the modified microchannel was effectively inhibited.A fused-silica capillary was connected to the chip through the specially designed channel.With this method,detection wavelength 214 nm,running voltage 5 kV,pH 4.5 and electrokinetic injection,UV detection for adenosine and L-tryptophan was achieved.The Rs of adenosine and L-tryptophan in modified microchannel can achieve 2.01.The RSD is 2.75%（Adenosine） and 1.54%（L-tryptophan） respectively.This research may be a novel method for PDMS microchip modification.