| dc.description.abstract | This paper presents a technique that combines electroless deposition with droplet deposition to deposit silver nanoparticles onto a porous silicon (PS) substrate. This method simplifies and enhances the efficiency of localized deposition, offering greater flexibility in the process. In the deposition process combining electroless deposition with droplet deposition, we achieved high coverage and strong Raman detection intensity. We also delved deeper into controlling the area of silver deposition by the droplet. The size of the deposition area directly affects the coverage rate of silver and the contact angle formed by that area, both of which influence subsequent detection results. Therefore, we optimized experimental results based on different deposition parameters, including silver deposition concentration and area.When using droplet lenses to enhance signals at the silver deposition points (LocAg-PS), we first simulated different contact angles formed by the droplets. After determining the optimal droplet contact angle, we studied the refraction effects of light entering the droplet lens at various positions. Through calibration with a camera lens, we adjusted the light to focus at or near the center of the droplet lens for detection. We then analyzed different sample deposition methods, including direct drying, pure water lenses, and sample lenses. The analysis revealed that sample lenses provided higher Raman detection signals.
In this paper, we discuss not only the impact of silver deposition concentration on Raman signals but also the enhancement of light intensity due to the smaller illuminated area caused by light refraction and focusing through the droplet. Additionally, we investigate the effects of light irradiation at different positions on the droplet surface on the silver deposition points. Experimental results showed that using pure water droplets and sample droplets for Raman detection achieved enhancement factors of 1.35×106 and 7.34×106, respectively. Compared to direct drying, the Raman detection signal was enhanced by 2 times and 6 times, respectively, without any noise generation. | en_US |