Abstract

Concentration procedures have always been implemented when trace analysis of compounds in real matrices is contemplated. A variety of concentration strategies have been reported aiming at decreasing the limits of detection (LODs). The optical concentration of the substance in solution is one of the novel concepts for the enhancement of the analytical sensitivity. In this study, the optical concentration has been measured by the trapping of gold nanoparticles ($100$ nm) dispersed in water at low-concentrations at the focal volume of the laser beam. The influence of factors such as the time of gold nanoparticle trapping, the size of the nanoparticles, the intensity of the laser beam, their solution concentration have been reported on the accumulation of gold nanoparticles in the solution. The results showed at different laser intensities, the capacity of the optical trap changed. At low concentrations of gold nanoparticles, the signal increased linearly with the concentration until the capacity of the optical trap was filled. Also, the best optical concentration efficiency was observed when the time of trapping increased to a period of 40 s. Under the optimum conditions, the relative concentration increase of gold nanoparticles was calculated across the range of $2\mathrm{ }$ to $25$ particles at the focal volume of the laser beam for the range from $7.20\times {10}^7\text{ to }5.8\times {10}^9$ particle/mL of gold nanoparticles in the solution at a laser intensity of $400$ mW. This approach may be used to quantitatively determine of gold nanoparticles, supermolecules, and other nanoparticles.

抽象的

当考虑对实际基质中的化合物进行痕量分析时，始终会执行浓缩程序。为了降低检测限（LODs），已经报道了多种浓缩策略。溶液中物质的光学浓度是提高分析灵敏度的新颖概念之一。在这项研究中，光学浓度是通过捕获金纳米颗粒（$100$纳米）以低浓度分散在水中，并聚焦在激光束的焦点处。已经报道了诸如金纳米粒子捕获时间，纳米粒子的尺寸，激光束的强度，它们的溶液浓度等因素对金纳米粒子在溶液中的累积的影响。结果表明，在不同的激光强度下，光阱的容量发生了变化。在低浓度的金纳米颗粒下，信号随浓度线性增加，直到光阱的容量被填满。另外，当捕获时间增加到40 s时，观察到最佳的光学聚集效率。在最佳条件下，计算了金纳米颗粒相对浓度的增加范围。$\mathrm{2个}\mathrm{ }$ 到 $25$ 激光束的聚焦体积处的粒子范围为 $7.20\times {10}^7\text{ 到 }5.8\times {10}^9$ 溶液中激光强度为10毫克/毫升的金纳米粒子 $400$兆瓦 该方法可用于定量确定金纳米颗粒，超分子和其他纳米颗粒。