高吸水性树脂溶胀热力学及吸水机理

分析了高吸水性树脂吸水的热力学本质，探讨了Flory公式的意义，通过简化的Flory公式得到吸水率与外部溶液离子强度的简单关系。同时，对高吸水性树脂在与水的相互作用以及溶胀过程进行了探讨，并以此为基础解释了一些吸水、保水现象。     

A multichannel microchip containing 16 chambers packed with antibody-functionalized beads for immunofluorescence assay

A multichannel chip containing 16 microchambers was developed for fast and sensitive immunoassays. In each chamber, antibody-functionalized nonmagnetic beads were applied as the solid phase to capture target antigens. Four types of IgGs (human, rabbit, chicken, and mouse) could be detected simultaneously by our combining this microchip with a sandwich immunoassay technique. A three-layer chip structure was investigated for integration of multiple processes, including washing, immune reaction, and detection, in one microchip. Moreover, the proposed chip design could improve batch-to-batch repeatability and avoid interferences between different channels without the preparation of complex microvalves. The total operation time of this system was less than 30 min, with a desirable detection limit of 0.2 pg/mL. The results indicate that the microfluidic platform is promising for the immunoassay of multiple clinical biomarkers.

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Nanoband electrode for high-performance in-channel amperometric detection in dual-channel microchip capillary electrophoresis

A nanoband electrode detector integrated with a dual-channel polydimethylsiloxane microchip is proposed for in-channel amperometric detection in microchip capillary electrophoresis. Gold nanoband electrodes, which were fabricated on SU-8 substrates with a 100-nm-width gold layer, were introduced into the dual-channel microchip to be an electrochemical detector. Due to the nano-sized width of the detector, the noise of the amperometric detection was significantly reduced, and a high separation resolution was achieved for monitoring the analytes. The detection sensitivity of the system was improved by high signal-to-noise ratio, and a low detection limit on microchip was obtained for p-aminophenol (2.09 nM). Because of the high resolution in measuring half-peak width, the plate number that is used to evaluate the separation efficiency was 1.5-fold higher than that using 50-μm-width electrochemical detector. The effect of sample injection time and data acquisition time on separation efficiency was investigated, and an attractive separation efficiency was achieved with a plate number up to 17,500.     

Applications of capillary electrophoresis in the fields of environmental,pharmaceutical, clinical,and food analysis (2019–2021)

So far, the potential of capillary electrophoresis in the application fields has been increasingly excavated due to the advantages of simple operation, short analysis time, high-resolution, less sample consumption, and low cost. This review examines the implementations and advancements of capillary electrophoresis in different application fields (environmental, pharmaceutical, clinical, and food analysis) covering the literature from 2019 to 2021. In addition, ultrasmall sample injection volume (nanoliter range) and short optical path lead to relatively low concentration sensitivity of the most frequently used ultraviolet-absorption spectrophotometric detection, so the pretreatment technology being developed has been gradually utilized to overcome this problem. Despite the review being focused on the development of capillary electrophoresis in the fields of environmental, pharmaceutical, clinical, and food analysis, the new sample pretreatment techniques of microextraction and enrichment fit excellently to capillary electrophoresis in recent three years are also described briefly.     

Digital droplet immunoassay based on a microfluidic chip with magnetic beads for the detection of prostate-specific antigen

Sensitive biomarker detection techniques are beneficial for both disease diagnosis and postoperative examinations. In this study, we report an integrated microfluidic chip designed for the immunodetection of prostate-specific antigens (PSAs). The microfluidic chip is based on the three-dimensional structure of quartz capillaries. The outlet channel extends to 1.8 cm, effectively facilitating the generation of uniform droplets ranging in size from 3 to 50 μm. Furthermore, we successfully immobilized the captured antibodies onto the surface of magnetic beads using an activator, and we constructed an immunosandwich complex by employing biotinylated antibodies. A key feature of this microfluidic chip is its integration of microfluidic droplet technology advantages, such as high-throughput parallelism, enzymatic signal amplification, and small droplet size. This integration results in an exceptionally sensitive PSA detection capability, with the detection limit reduced to 7.00 ± 0.62 pg/mL.