Xing Lixiang, Wang Cui, Cao Yi, Zhang Jihui, Xia Haibing
State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, P. R. China.
School of Materials Science & Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, P. R. China.
Nanoscale. 2021 Sep 17;13(35):14925-14934. doi: 10.1039/d1nr03864h.
In this work, macroscopical monolayer films of ordered arrays of gold nanoparticles (MMF-OA-Au NPs) are successfully prepared at the interfaces of toluene-diethylene glycol (DEG) with a water volume fraction of 10% (no more than 25%), which can greatly reduce the electrostatic repulsion among NPs during the self-assembly due to the quick transfer of the remaining citrate ions into the DEG solutions containing water. Thanks to the uniformity in the intensity of SERS signals, the as-prepared MMF-OA-Au NPs transferred onto polydimethylsiloxane (PDMS) as SERS substrates (MMF-OA-Au NP@PDMS) can achieve quantitative detection of the analytes (such as crystal violet and malachite green) in aqueous solutions. Moreover, MMF-OA-Au NP@PDMS as SERS-based pH sensors can directly determine the pH value of the aqueous solution in the range of 3 to 10 by means of the established well-defined linear relationship with the intensity of the peak of COO without any calibration, instead of the intensity ratio of the Raman peaks of COO to 8a with further calculation. In addition, the as-prepared SERS-based pH sensors can still have excellent long-term durability.
在这项工作中，成功地在水体积分数为10%（不超过25%）的甲苯-二甘醇（DEG）界面制备了金纳米粒子有序阵列的宏观单层膜（MMF-OA-Au NPs），由于剩余的柠檬酸根离子迅速转移到含水的DEG溶液中，这可以大大降低自组装过程中纳米粒子之间的静电排斥力。由于表面增强拉曼散射（SERS）信号强度的均匀性，转移到聚二甲基硅氧烷（PDMS）上作为SERS基底的制备好的MMF-OA-Au NPs（MMF-OA-Au NP@PDMS）能够对水溶液中的分析物（如结晶紫和孔雀石绿）进行定量检测。此外，MMF-OA-Au NP@PDMS作为基于SERS的pH传感器，通过与-COO峰强度建立的明确线性关系，无需任何校准，可直接测定3至10范围内水溶液的pH值，而不是通过进一步计算-COO与8a拉曼峰的强度比。此外，制备好的基于SERS的pH传感器仍具有出色的长期耐久性。
