Detecting gold and polystyrene nanoparticles under UV microscope
Xinyu Fang, Jérome Wenger
Aix Marseille Univ, CNRS, Centrale Med, Institut Fresnel, AMUTech
"The study focuses on using a UV microscope to detect the extinction properties of gold (Au) and polystyrene (PS) nanoparticles. Typically, nanoparticles are analyzed for their extinction in visible and infrared spectra, but this research emphasizes the UV spectrum. The setup includes a UV microscope with a backside illuminated CMOS camera, a Zeiss objective, and a 285 nm LED.
By varying the size of nanoparticles, we observe changes in their extinction spectra in different images under UV illumination, and correlate the experimental data with numerical values. Then, the minimum detectable diameter of nanoparticle under UV camera can be estimated accordingly. If there is only shot noise considered, the minimum detectable diameter of gold is around 22nm, while for polystyrene, it is 42nm. However, considering the actual noise, adjust these values to 29 nm for gold and 52 nm for polystyrene.
Overall, this work provides a detailed examination of the use of UV microscope for detecting gold and polystyrene nanoparticles. By analyzing the UV and SEM images and correlating experimental data with theoretical values, offering a foundation for future advancements in nanoparticle analysis and application. Apart from that, the study also emphasizes the importance of optimizing experimental conditions to achieve the best detection limits."
The UV and SEM images of gold nanoparticles with 100nm figure(a) and 80nm figure(b). Figure(c) shows the relationship between extinction cross-section, extinction and diameter of gold nanoparticles. Here, dots are experimental data, solid line refers to numerical value.