化学
检出限
电动现象
分子印迹聚合物
增塑剂
拉曼散射
分子
吸附
纳米颗粒
色谱法
纳米技术
拉曼光谱
选择性
有机化学
材料科学
催化作用
物理化学
物理
光学
作者
Yuanyuan Yang,Yuanting Li,Wenlei Zhai,Xuejian Li,Dan Li,Hualin Lin,Sheng Han
标识
DOI:10.1021/acs.analchem.0c03652
摘要
Nonspecific binding and weak spectral discernment are the main challenges for surface-enhanced Raman scattering (SERS) detection, especially in real sample analysis. Herein, molecularly imprinted polymer (MIP)-based core–shell AuNP@polydopamine (AuNP@PDA-MIP) nanoparticles (NPs) are designed and immobilized on an electrochemically reduced MoS2-modified screen-printed electrode (SPE). This portable electrochemical–Raman interface offers the dual functions of electrokinetic preseparation (EP) and MIP trapping of charged molecules so that a reliable SERS recognition with molecular selectivity and high sensitivity can be achieved. Core–shell AuNP@PDA-MIP NPs can be controllably synthesized, possess predesigned specific recognition, and provide “hot spots” at the junction of NPs. The introduction of an electric field enables the autonomous exclusion and separation of similarly charged molecules as well as attraction and concentration of the oppositely charged molecules by electrostatic attraction. Subsequently, the specific MIP recognition cavities allow selective adsorption of targets on the interface without the interference of analogues. Owing to the distinctive design of the multiple coupling separation, trapping, and enrichment strategies, the MIP-based SERS-active interface can be used for label-free detection of charged molecules in real samples without pretreatment. As a proof-of-concept study, label-free SERS detection of charged phthalate plasticizers (PAEs) was demonstrated with a detection limit as low as 2.7 × 10–12 M for dimethyl phthalate (DMP) and 2.3 × 10–11 M for di(2-ethylhexyl) phthalate (DEHP). This sensing strategy for in situ SERS analysis of charged pollutants or toxins holds vast promises for a wide range of in-field applications.
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