Shu Tong, Shen Qiming, Wan Yu, Zhang Wei, Su Lei, Zhang Xueji, Serpe Michael J
Beijing Key Laboratory for Bioengineering and Sensing Technology, Research Center for Bioengineering and Sensing Technology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing Beijing 100083 P. R. China.
Department of Chemistry, University of Alberta Edmonton Alberta Canada T6G 2G2
RSC Adv. 2018 Apr 24;8(28):15567-15574. doi: 10.1039/c8ra02215a. eCollection 2018 Apr 23.
Silver nanoparticles (AgNPs) were generated inside the network structure of poly(-isopropylacrylamide)--acrylic acid (pNIPAm--AAc) microgels that were sandwiched between two thin Au layers (15 nm) of an etalon. This was done by introducing Ag to the etalons composed of deprotonated microgels, followed by its subsequent reduction with NaBH. The resultant microgels were collected and then characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), verifying the loading of AgNPs with relatively uniform diameter (5-7 nm) within the microgels. Furthermore, the optical properties of the resultant etalons and their response to HO were evaluated by reflectance spectroscopy. Specifically, upon the addition of HO, the AgNP-loaded etalons exhibited both a red shift in the position of the reflectance peaks and an increase in reflected wavelength intensity. We hypothesize that the dual signal response of the devices was a result of oxidative decomposition of the AgNPs, enabling the microgels to swell and for more light to be reflected (due to the loss of the light absorbing AgNPs). Finally, we showed that the AgNPs could be regenerated in the used etalons multiple times without a loss in performance. This work provides a cost-effective means to detect HO, which could be modified to sense a variety of other species of physiological and environmental importance through rationally loading other functional nanomaterials.
银纳米颗粒（AgNPs）在夹于标准具的两个薄金层（15纳米）之间的聚（N-异丙基丙烯酰胺）-丙烯酸（pNIPAm-AAc）微凝胶的网络结构内生成。这是通过将银引入由去质子化微凝胶组成的标准具中，随后用硼氢化钠对其进行还原实现的。收集得到的微凝胶，然后通过透射电子显微镜（TEM）、傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）对其进行表征，证实了在微凝胶内负载了直径相对均匀（5-7纳米）的AgNPs。此外，通过反射光谱评估了所得标准具的光学性质及其对过氧化氢（H₂O₂）的响应。具体而言，加入H₂O₂后，负载AgNP的标准具在反射峰位置出现红移，并且反射波长强度增加。我们推测该器件的双重信号响应是AgNPs氧化分解的结果，使得微凝胶膨胀并反射更多光（由于光吸收性AgNPs的损失）。最后，我们表明在使用过的标准具中AgNPs可以多次再生而性能无损失。这项工作提供了一种经济高效的检测H₂O₂的方法，通过合理负载其他功能纳米材料，该方法可以进行修改以检测各种其他具有生理和环境重要性的物质。
