Chen Qing, Pang Kun, Tang Qiao, Huang Jie, Dong Qianmin, Liang Pei
College of Optical and Electronic Technology, China Jiliang University, 310018 Hangzhou, China.
Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Modern Science and Technology, China Jiliang University, Hangzhou 310018, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 Jan 15;325:125133. doi: 10.1016/j.saa.2024.125133. Epub 2024 Sep 18.
In order to solve the problem of poor sensitivity and selectivity of conventional SERS substrates, we synthesized MoWS@AgS nanosheets in this paper by a two-step hydrothermal method. The structure and morphology of the synthesized MoWS@AgS nanosheets were characterized by XRD and SEM,respectively. The results show that the MoWS@AgS nanosheet has an irregular layered structure. Further, the SERS properties of MoWS@AgS nanosheets were tested by using rhodamine 6G (R6G), crystalline violet (CV), and 4-mercaptobenzoic acid (4-MBA) as probe molecules, respectively. The test results demonstrated that the nanosheets were specific to R6G and CV probe molecules, and the mechanism of selectivity was due to CT enhancement. In addition, MoWS@AgS exhibits ultrahigh sensitivity in R6G and CV, with the corresponding detection limit of both reached 10 M. And linear fitting of the peak intensities was carried out, with the R coefficient of 0.981 and 0.951, respectively. Finally, the relative standard deviations (RSDs) of this Mo1-xWxS2@Ag2S nanosheets was obtained to be 8.56 % by test 1 × 10 M R6G at the characteristic peak 613 cm, which represents excellent detection repeatability. The MoWS@AgS nanosheets are rich in edge-active sites favorable for charge transfer, which can enhance the SERS signals of the target molecules better. Besides, the Raman detection of the surface of MoWS@AgS nanosheets using nitrofurantoin (NFT) also reached a detection limit of 10 M. MoWS@AgS nanosheets substrates can find applications in medicine and provide new strategies for improving the SERS performance.
为了解决传统表面增强拉曼散射（SERS）基底灵敏度和选择性差的问题，本文采用两步水热法合成了MoWS@AgS纳米片。分别通过X射线衍射（XRD）和扫描电子显微镜（SEM）对合成的MoWS@AgS纳米片的结构和形貌进行了表征。结果表明，MoWS@AgS纳米片具有不规则的层状结构。此外，分别以罗丹明6G（R6G）、结晶紫（CV）和4-巯基苯甲酸（4-MBA）作为探针分子，测试了MoWS@AgS纳米片的SERS性能。测试结果表明，该纳米片对R6G和CV探针分子具有特异性，其选择性机制归因于电荷转移增强。此外，MoWS@AgS对R6G和CV表现出超高灵敏度，两者的相应检测限均达到10⁻¹⁰ M。并对峰强度进行了线性拟合，R系数分别为0.981和0.951。最后，通过在特征峰613 cm⁻¹处测试1×10⁻⁸ M的R6G，得到该Mo1-xWxS2@Ag2S纳米片的相对标准偏差（RSD）为8.56%，这代表了优异的检测重复性。MoWS@AgS纳米片富含有利于电荷转移的边缘活性位点，能够更好地增强目标分子的SERS信号。此外，使用呋喃妥因（NFT）对MoWS@AgS纳米片表面进行拉曼检测时，检测限也达到了10⁻⁸ M。MoWS@AgS纳米片基底在医学领域具有应用前景，并为提高SERS性能提供了新策略。
