单分子磁镊技术的微纳化研究

单分子磁镊技术通过磁场控制超顺磁珠小球对单分子施加机械力，并使用显微成像追踪磁珠小球，获得磁珠小球的三维位置信息，拟合单分子产生的机械形变。相较于其他单分子力谱技术，磁镊不需要高强度的辐照，可以应用于单个分子和活细胞，具有非侵入、三维操纵等优点，并允许对样品施加拉伸和扭曲作用力，被广泛应用在核酸和蛋白质的力学检测中。国内外课题组在研究生物问题过程中将单分子磁镊技术推广到各种应用场景，在实验设计和单分子动力学方面具有深刻见解。然而，就磁镊设备本身而言，在单一的微流道中难以实现高通量，且现有设备的速度和精度都有待提升。本研究基于目前的单分子磁镊系统，研究了磁镊芯片的制备和生化修饰方法，利用驱动电机改进了磁镊实验的自动化，比较和研究了磁镊明场成像系统与暗场成像系统的性能差异，并尝试使用纳米压印修饰磁镊芯片以提高实验通量。结果表明，芯片化的研究方式提升了磁镊实验的便携性，控制驱动电机移动位移台将磁镊实验过程整合为自主完成，使用实验脚本自动化可以矫正由单分子随机连接磁珠小球带来的z轴测量误差。通过改进激光照明透射式暗场成像系统可将系统z轴测量标准差由传统LED照明成像系统的5.8 nm降低至1.6 nm，提升了系统的测量精度。进一步改进反射式成像系统可以避免磁头对成像画面造成的影响，获得磁珠小球的拉伸实验数据。使用激光照明带来更高的亮度，将系统的采样速度由100 Hz提升至500 Hz，提升了磁镊设备的速度。纳米压印技术的引入将视野中的磁珠小球数量提升2-3倍，提高了实验通量。基于以上结果，本文还探讨了影响磁镊设备性能的因素，并提出了进一步改进磁镊设备性能的研究方向。

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