Primary cell wall (PCW) is a rigid yet flexible cell wall surrounding plant cells and it plays key roles in plant growth, cell differentiation, intercellular communication, water movement and defence. As a technique widely used to study the characteristics of mammalian cells, electrical impedance spectroscopy (EIS) is rarely used in plant science. In this work, we designed and fabricated an EIS based biosensor coupled with microfluidic platform to investigate the formation process of PCWat the single-cell level. Arabidopsis mesophyll cells with completely regenerated PCW showed significantly higher impedance values compared to the nascent protoplasts without PCW, demonstrating that PCW formation caused a dramatic change in cell electrical properties. The device could also discriminate plant mutant cells with modified PCW compositions, thus provided a novel tool for physical phenotyping of plant cells. The dose-dependent effects of exogenously applied auxin on PCW regeneration were corroborated on this platform which revealed its potential to sensitively detect the influences of in vitro stimuli. This work not only provided one novel application of impedance-based biosensor to characterize a plant-specific developmental event, but also revealed the promises of EIS integrated microfluidic system as a sensitive, time-effective and low-cost platform to characterize single plant cells and make new scientific discoveries in plant science.

原代细胞壁（PCW）是围绕植物细胞的刚性而灵活的细胞壁，在植物生长，细胞分化，细胞间通讯，水分运动和防御中起着关键作用。作为广泛用于研究哺乳动物细胞特征的技术，电阻抗光谱法（EIS）在植物科学中很少使用。在这项工作中，我们设计和制造了基于EIS的生物传感器，并结合了微流体平台，以研究单细胞水平PCW的形成过程。拟南芥与不具有PCW的新生原生质体相比，具有完全再生的PCW的叶肉细胞显示出明显更高的阻抗值，表明PCW的形成引起细胞电特性的巨大变化。该装置还可以通过修饰的PCW成分来区分植物突变细胞，从而为植物细胞的物理表型提供了一种新颖的工具。在该平台上证实了外源生长素对PCW再生的剂量依赖性作用，这表明其潜在地灵敏地检测体外的影响刺激。这项工作不仅为基于阻抗的生物传感器提供了一种新颖的应用来表征植物特有的发育事件，而且还揭示了EIS集成微流控系统有望成为一种灵敏，省时且低成本的平台，用于表征单个植物细胞和在植物科学方面取得新的科学发现。