超支化聚酰胺酯改性聚甲基丙烯酸甲酯微流控芯片的制备及其在生物分子分离检测中的应用

Preparation of poly(methyl acrylate) microfluidic chips with surface-modified by hyperbranched polyamide ester and their application in the separation of biomolecules

利用亲水性超支化聚酰胺酯通过化学键合的方法对聚甲基丙烯酸甲酯(PMMA)微流控芯片的表面进行改性。对改性后PMMA微流控芯片的表面进行了接触角的测定,利用扫描电子显微镜(SEM)和体视显微镜观察了改性后芯片的表面形貌。结果表明,改性后的PMMA微流控芯片表面形成了一层均匀、致密、连续的亲水性涂层,芯片表面的亲水性得到了明显提高,接触角由未改性时的89.9°降低到29.5°。改性后芯片的电渗流较之改性前明显降低。利用芯片对腺苷和L-赖氨酸两种生物分子进行了分离检测。两种生物分子实现了完全分离,所得到的检测峰峰形尖锐,分离清晰。对腺苷和L-赖氨酸的分离柱效(理论塔板数)分别高达8.44×104塔板/m和9.82×104塔板/m,分离度(Rs)达到5.31,均远远高于未改性的芯片。改性后的芯片具有良好的分离时间重现性。本研究为提高PMMA微流控芯片的亲水性和应用范围提供了一种新的有效方法。

The surface of poly（methyl acrylate）（PMMA） microfluidic chips were modified using hyperbranched polyamide ester via chemical bonding.The contact angles of the modified chips were measured.The surface morphology was observed by scanning electron microscope（SEM） and stereo microscope.The results showed that the surface of the modified chips was coated by a dense,uniform,continuous,hydrophilic layer of hyperbranched polyamide ester.The hydrophilic of the chip surface was markedly improved.The contact angle of the chips modified decreased from 89.9° to 29.5°.The electro osmotic flow（EOF） in the modified microchannel was lower than that in the unmodified microchannel.Adenosine and L-lysine were detected and separated via the modified PMMA microfluidic chips.Compared with unmodified chips,the modified chips successfully separated the two biomolecules.The detection peaks were clear and sharp.The separation efficiencies of adenosine and L-lysine were 8.44×104 plates/m and 9.82×104 plates/m respectively,and the resolutions（Rs） was 5.31.The column efficiencies and resolutions of the modified chips were much higher than those of the unmodified chips.It was also observed that the modified chips possessed good reproducibility of migration time.This research may provide a new and effective method to improve the hydrophilicity of the PMMA surface and the application of PMMA microfluidic chips in the determination of trace biomolecules.