School of Chemical and Environmental Engineering, Shanghai Institute of Technology, No. 100 Haiquan Road, Shanghai, 201418, People's Republic of China.
Department of Forensic Medicine, Nanjing Medical University, Nanjing, 211166, People's Republic of China.
Mikrochim Acta. 2020 Mar 7;187(4):203. doi: 10.1007/s00604-020-4201-3.
A new portable molecular imprinting polymer (MIP)-SERS nanoprobe is fabricated by a convenient electrochemical method. Single-layered MoS is electrochemically reduced on a screen-printed electrode as the scaffold. Functional monomers o-phenylenediamine (oPD), template theophylline (THP), and SERS-active Au nanoparticles (AuNPs) are then one-step electropolymerized on the scaffold. The morphology of the nanoprobe is found to be a three-dimensional and porous structure. The abundant AuNPs with the size of 45~50 nm are trapped within the growing MIP instead of being confined to the surface. The thickness of MIP film is calculated to 25.1 nm. The nanoprobe displays a strong SERS effect for THP using 532 nm as excitation wavelength with a detection limit (LOD) of 0.01 nM. The SERS peak intensity at 1487 cm increases linearly with the concentration of THP in the range 0.1 nM to 0.1 mM. After the template is removed, the imprint-removed nanoprobe is generated for selective binding of THP. The re-binding kinetics study implies the portable MIP-SERS nanoprobe can reach the adsorption equilibrium within 8 min. This nanoprobe exhibits low SERS interference for structural analogues theobromine (THB) and caffeine (CAF). The nanoprobe was employed to THP determination in tea drink samples, with recoveries ranging from 99.0 to 102.0% and relative standard deviations of < 5.0%. Graphical abstractSchematic representation of a portable molecular imprinting SERS nanoprobe used for selective and sensitive theophylline recognition. The nanoprobe is fabricated by one-step electropolymerized o-phenylenediamine (oPD), theophylline, and electroreduced Au nanoparticles (AuNPs) on reduced MoS (rMoS) modified screen-printed electrode (SPE).
一种新型的便携式分子印迹聚合物（MIP）-SERS 纳米探针通过一种方便的电化学方法制备。单层 MoS 通过电化学还原在丝网印刷电极上作为支架。然后，功能单体邻苯二胺（oPD）、模板茶碱（THP）和 SERS 活性金纳米粒子（AuNPs）在支架上一步电聚合。纳米探针的形态被发现是一种三维多孔结构。大量尺寸为 45~50nm 的 AuNPs 被捕获在生长的 MIP 内，而不是局限于表面。MIP 膜的厚度计算为 25.1nm。该纳米探针在 532nm 激发波长下对 THP 显示出很强的 SERS 效应，检测限（LOD）为 0.01nM。在 1487cm 处的 SERS 峰强度随着 THP 浓度在 0.1 nM 至 0.1 mM 的范围内线性增加。模板去除后，生成印迹去除的纳米探针以选择性结合 THP。再结合动力学研究表明，便携式 MIP-SERS 纳米探针可以在 8 分钟内达到吸附平衡。该纳米探针对结构类似物可可碱（THB）和咖啡因（CAF）的 SERS 干扰较低。该纳米探针用于茶饮料样品中 THP 的测定，回收率在 99.0%至 102.0%之间，相对标准偏差小于 5.0%。
