A series of gold nanoparticles were synthesized by stepwise growth method under the condition of citrate as a reducing agent and stabilizer. The optical properties with the maximum absorption wavelength (λ_max) and electrochemical properties of the oxidation potential (E_p) dependence on the particle size were analyzed. The method of calculating the particle size from the UV-visible spectrum and the electrochemical oxidation peak was deduced, following the theoretical prediction trend and consistent with previous observations. Furthermore, we investigated the application performance based on the electrochemical catalytic activity and the aggregation of the spherical gold nanoparticles using L-cysteine as a target. The results indicated that the optical and electrochemical properties of the gold nanoparticles to L-cysteine were closely related to the particle size of gold nanoparticles. With the increased size of the nanoparticles, the full width at half maximum in the UV-visible absorption spectrum increased and the electrochemical oxidation potential was positively shifted.

在柠檬酸盐作为还原剂和稳定剂的条件下，通过逐步生长的方法合成了一系列金纳米颗粒。具有最大吸收波长（_λmax）的光学性质和氧化电位的电化学性质（E _p）对颗粒大小的依赖性进行了分析。推导了从紫外可见光谱和电化学氧化峰计算粒径的方法，遵循理论预测趋势并与先前的观察结果一致。此外，我们研究了基于L-半胱氨酸为目标的球形金纳米颗粒的电化学催化活性和聚集作用的应用性能。结果表明，金纳米粒子对L-半胱氨酸的光学和电化学性质与金纳米粒子的粒径密切相关。随着纳米颗粒尺寸的增加，UV-可见吸收光谱中的半峰全宽增加，并且电化学氧化电势正向移动。