Zhang Nan, Lv Haiyang, Wang Jihong, Yang Zhanye, Ding Yanru, Zhao Bing, Tian Yuan
College of Chemistry, Jilin Province Research Center for Engineering and Technology of Spectral Analytical Instruments, Jilin University, Changchun, 130012, P. R. China.
State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012, P. R. China.
Anal Methods. 2023 Feb 23;15(8):1047-1053. doi: 10.1039/d2ay01825j.
Residues of sulfadimethoxine (SDM) in animal-derived foods have attracted widespread public concern. Herein, we propose an aptamer-based colorimetric/SERS dual-mode sensing strategy for the determination of SDM based on hexadecyl trimethyl ammonium bromide (CTAB) induced aggregation of nanoparticles. In the absence of SDM, the SDM aptamer formed a supramolecular composite with CTAB, and the 4-mercaptopyrimidine functionalized gold nanoparticles (AuNPs@4-MPY) remained dispersed due to the lack of CTAB. Upon the addition of SDM, the SDM aptamer preferentially combined with SDM, resulting in the release of CTAB and subsequent aggregation of AuNPs@4-MPY, and the solution color changed from red to blue and presented a dynamic UV-absorbance curve based on different aggregation states. On the other hand, when, gold-silver core-shell nanoparticles (Au@AgNPs) were added additionally, the released CTAB narrowed the nanogap between AuNPs@4-MPY and Au@AgNPs, thus exhibiting enhanced SERS intensity of 4-MPY. This strategy achieved colorimetric detection of SDM with a linear range of 4.00-200.00 ng mL and a detection limit of 2.41 ng mL, while SERS had a detection range of 1.20-120.00 ng mL with a detection limit of 0.89 ng mL. This strategy is simple and cost-effective for the rapid detection of SDM within 20 minutes. It was further applied for the detection of SDM in spiked milk and honey samples with satisfactory recoveries. Therefore, it exhibits great potential for fast and on-site SDM detection.
动物源性食品中磺胺二甲氧嘧啶（SDM）的残留引起了公众的广泛关注。在此，我们提出了一种基于适配体的比色/表面增强拉曼光谱（SERS）双模式传感策略，用于基于十六烷基三甲基溴化铵（CTAB）诱导的纳米颗粒聚集来测定SDM。在没有SDM的情况下，SDM适配体与CTAB形成超分子复合物，由于缺乏CTAB，4-巯基嘧啶功能化的金纳米颗粒（AuNPs@4-MPY）保持分散状态。加入SDM后，SDM适配体优先与SDM结合，导致CTAB释放，随后AuNPs@4-MPY聚集，溶液颜色从红色变为蓝色，并基于不同的聚集状态呈现动态紫外吸收曲线。另一方面，当额外添加金银核壳纳米颗粒（Au@AgNPs）时，释放的CTAB缩小了AuNPs@4-MPY与Au@AgNPs之间的纳米间隙，从而使4-MPY的SERS强度增强。该策略实现了SDM的比色检测，线性范围为4.00 - 200.00 ng/mL，检测限为2.41 ng/mL，而SERS的检测范围为1.20 - 120.00 ng/mL，检测限为0.89 ng/mL。该策略简单且成本效益高，可在20分钟内快速检测SDM。它进一步应用于加标牛奶和蜂蜜样品中SDM的检测，回收率令人满意。因此，它在快速现场检测SDM方面具有巨大潜力。
