Microchip electrophoresis is a separation technology that involves fluid manipulation in a microchip; the advantages of this technique include high separation efficiency, low sample consumption, and fast and easy multistep integration. Microchip electrophoresis has been widely used to rapidly separate and analyze complex samples in biology and medicine. In this paper, we review the research progress on microchip electrophoresis, explore the fabrication and separation modes of microchip materials, and discuss their applications in the detection and analysis of biological samples. Research on microchip materials can be mainly categorized into chip materials, channel modifications, electrode materials, and electrode integration methods. Microchip materials research involves the development of silicon, glass, polydimethylsiloxane and polymethyl methacrylate-based, and paper electrophoretic materials. Microchannel modification research primarily focuses on the dynamic and static modification methods of microchannels. Although chip materials and fabrication technologies have improved over the years, problems such as high manufacturing costs, long processing time, and short service lives continue to persist. These problems hinder the industrialization of microchip electrophoresis. At present, few static methods for the surface modification of polymer channels are available, and most of them involve a combination of physical adsorption and polymers. Therefore, developing efficient surface modification methods for polymer channels remains a necessary undertaking. In addition, both dynamic and static modifications require the introduction of other chemicals, which may not be conducive to the expansion of subsequent experiments. The materials commonly used in the development of electrodes and processing methods for electrode-microchip integration include gold, platinum, and silver. Microchip electrophoresis can be divided into two modes according to the uniformity of the electric field: uniform and non-uniform. The uniform electric field electrophoresis mode mainly involves micro free-flow electrophoresis and micro zone electrophoresis, including micro isoelectric focusing electrophoresis, micro isovelocity electrophoresis, and micro density gradient electrophoresis. The non-uniform electric field electrophoresis mode involves micro dielectric electrophoresis. Microchip electrophoresis is typically used in conjunction with conventional laboratory methods, such as optical, electrochemical, and mass spectrometry, to achieve the rapid and efficient separation and analysis of complex samples. However, the labeling required for most widely used laser-induced fluorescence technologies often involves a cumbersome organic synthesis process, and not all samples can be labeled, which limits the application scenarios of laser-induced fluorescence. The applications of unlabeled microchip electrophoresis-chemiluminescence/dielectrophoresis are also limited, and simplification of the experimental process to achieve simple and rapid microchip electrophoresis remains challenging. Several new models and strategies for high throughput in situ detection based on these detection methods have been developed for microchip electrophoretic systems. However, high throughput analysis by microchip electrophoresis is often dependent on complex chip structures and relatively complicated detection methods; thus, simple high throughput analytical technologies must be further explored. This paper also reviews the progress on microchip electrophoresis for the separation and analysis of complex biological samples, such as biomacromolecules, biological small molecules, and bioparticles, and forecasts the development trend of microchip electrophoresis in the separation and analysis of biomolecules. Over 250 research papers on this field are published annually, and it is gradually becoming a research focus. Most previous research has focused on biomacromolecules, including proteins and nucleic acids; biological small molecules, including amino acids, metabolites, and ions; and bioparticles, including cells and pathogens. However, several problems remain unsolved in the field of microchip electrophoresis. Overall, microchip electrophoresis requires further study to increase its suitability for the separation and analysis of complex biological samples.
微芯片电泳技术是在微芯片中通过流体操控实现电泳分离的分析技术,具有分离效率高、样品量消耗少、分析速度快、易于集成等优势,已广泛应用于生物、医药等复杂样品的快速分离分析中。本文综述了微芯片电泳技术在微芯片材料、电泳模式、检测方式及生物样品分离分析等方面的研究进展。微芯片材料包括芯片材料与通道修饰方法以及电极材料与电极集成方式。芯片材料主要包括硅、玻璃、纸材料、聚二甲基硅氧烷和聚甲基丙烯酸甲酯等聚合物材料;通道修饰方法是指在微通道上的动、静修饰方法。电极材料与电极集成方式包括研制电极所需的金、铂、银材料以及将电极与微芯片集成的加工方式。根据施加电场是否均匀,微芯片电泳技术可分为均匀和非均匀电场两种电泳模式。均匀电场模式主要为微自由流电泳和微区带电泳,包括微等电聚焦电泳、微等速电泳、微密度梯度电泳等;非均匀电场模式主要为微介电泳。微芯片电泳技术通常与光谱、电化学和质谱等分析检测技术联用,实现复杂样品的快速、高效分离分析。近年来微芯片电泳在高通量和原位分离分析方面还发展了许多新模式和新策略。本文介绍了微芯片电泳技术在生物大分子、生物小分子、生物粒子等生物样品中的分离分析进展,并展望了微芯片电泳技术在生物样品分离分析中的发展趋势。
Keywords: biological samples; microchip electrophoresis; research progress; separation and analysis.