Pure and polymer coated (PVP and PVA) gold nanoparticles (AuNPs) with 0.001 and 0.002 M concentrations were synthesised by chemical method. Transmission electron microscopy (TEM) images showed that the size of nanoparticles is below 50 nm whereas the selected area electron diffraction (SAED) pattern indicated cubic structure with lattice parameter of 4.09 for each sample. The absorption bands for all these samples lie between 500 and 550 nm as observed from UV–vis spectra. The photoluminescence (PL) spectra taken at 300 nm excitation wavelength showed emission between 415 and 430 nm whereas the particle size determined from particle size analyser lies below 100 nm for all samples. The ultrasonic velocity measured as a function of temperature showed the decrement above 50 C for PVP and PVA coated AuNPs. The antimicrobial activity for these above taken concentrations of gold samples showed negative effect, whereas higher concentration of AuNPs of 0.005 M showed the positive effect for gram-positive and gram-negative bacteria.

通过化学方法合成了浓度为 0.001 和 0.002 M 的纯和聚合物涂层（PVP 和 PVA）金纳米粒子 (AuNPs)。透射电子显微镜 (TEM) 图像显示纳米颗粒的尺寸低于 50 nm，而选区电子衍射 (SAED) 图案显示立方结构，每个样品的晶格参数为 4.09。从紫外可见光谱观察，所有这些样品的吸收带都在 500 到 550 nm 之间。在 300 nm 激发波长处拍摄的光致发光 (PL) 光谱显示在 415 和 430 nm 之间发射，而从粒度分析仪确定的所有样品的粒度均低于 100 nm。作为温度函数测量的超声波速度表明，PVP 和 PVA 涂覆的 AuNP 在 50°C 以上下降。