Gold nanoparticles (AuNPs) have widely used for various biological applications, such as drug screening, photo-thermal therapy, and biosensing. In particular, the synthesis of AuNPs with narrow size distribution plays an important role in increasing the efficiency of nanoparticle-mediated biosensors. However, the conventional synthesis methods (e.g., citrate reduction method) still suffer from controlling the sizes of the nanoparticles. In this paper, we present the synthesis method of homogeneous AuNPs using a droplet-based microfluidic chip. Prior to experiments, we optimized the size of droplets using a simulation software for stable droplet generation. We demonstrated that the nanoparticles synthesized in our microfluidic chip system showed a narrower size distribution and a higher reproducibility compared to conventional batch synthesis. Furthermore, we observed that the signal of anti-horseradish peroxidase (HRP) was significantly enhanced by the droplet-based microfluidic chip. Therefore, our synthesis method of homogeneous AuNPs could play an important role in improving the efficiency of AuNPs-based sensing signals.

金纳米颗粒（AuNPs）已广泛用于各种生物学应用，例如药物筛选，光热疗法和生物传感。特别地，具有窄尺寸分布的AuNP的合成在提高纳米粒子介导的生物传感器的效率中起重要作用。然而，常规的合成方法（例如，柠檬酸盐还原法）仍然受控制纳米颗粒的尺寸的困扰。在本文中，我们介绍了使用基于液滴的微流控芯片合成均质AuNPs的方法。在进行实验之前，我们使用仿真软件优化了液滴的大小，以稳定液滴的产生。我们证明了在我们的微流控芯片系统中合成的纳米粒子与常规的批处理合成相比显示出更窄的尺寸分布和更高的重现性。此外，我们观察到基于液滴的微流控芯片显着增强了抗辣根过氧化物酶（HRP）的信号。因此，我们的均质AuNPs的合成方法可能在提高基于AuNPs的传感信号的效率中起重要作用。