Implementation of Molecularly Imprinted Polymer Beads for Surface Enhanced Raman Detection

Abstract

Molecularly imprinted polymers (MIPs) have a predesigned molecular recognition capability that can be used to build robust chemical sensors. MIP-based chemical sensors allow label-free detection and are particularly interesting due to their simple operation. In this work we report the use of thiol-terminated MIP microspheres to construct surfaces for detection of a model organic analyte, nicotine, by surface enhanced Raman scattering (SERS). The nicotine-imprinted microspheres are synthesized by RAFT precipitation polymerization and converted into thiol-terminated microspheres through aminolysis. The thiol groups on the MIP surface allow the microspheres to be immobilized on a gold-coated substrate. Three different strategies are investigated to achieve surface enhanced Raman scattering in the vicinity of the imprinted sites: (1) direct sputtering of gold nanoparticles, (2) immobilization of gold colloids through the MIP's thiol groups, and (3) trapping of the MIP microspheres in a patterned SERS substrate. For the first time we show that large MIP microspheres can be turned into selective SERS surfaces through the three different approaches of assembly. The MIP-based sensing surfaces are used to detect nicotine to demonstrate the proof of concept. As synthesis and surface functionalization of MIP microspheres and nanoparticles are well established, the methods reported in this work are handy and efficient for constructing label-free chemical sensors, in particular for those based on SERS detection.

Quantitative Detection of Trace Level Cloxacillin in Food Samples Using Magnetic Molecularly Imprinted Polymer Extraction and Surface-Enhanced Raman Spectroscopy Nanopillars

“…However, to the best of our knowledge, the use of MMIPs to directly extract cloxacillin from food samples has seldom been demonstrated. Surface-enhanced Raman spectroscopy (SERS) is a powerful analytical method, which uses nanoplasmonic hot spots to magnify chemical information of analytes adsorbed to or near the surface of noble metals 10,11 . SERS biosensors have demonstrated an ability to detect small molecule analytes with high sensitivity and short analysis times 12 .…”

Precision Target Guide Strategy for Applying SERS into Environmental Monitoring

“…Zhang et al proposed a ligand replacement approach to rapid determination of penicilloic acid in the penicillin by using a molecularly imprinted monolayer as recognition surface, which efficiently excluded the interference of penicillin and provided a selective determination down to 0.1‰ (w/w) [56]. Similarly, thiol-terminated MIP microspheres which have been immobilized on a gold-coated substrate were used for the selective capture of nicotine, showing good capture efficiency and SERS response [57]. In considering of using MIPs techniques for selective SERS detection, two key points should be kept in mind.…”

Probing cavity versus surface preference of fluorescent template molecules in molecularly imprinted polystyrene microspheres

“…The analytical tools that are generally used for characterization are HPLC, GCMS, potentiometer, and so forth . Other techniques which could be used for detection and quantification of a template in MIP are surface plasmon resonance or quartz crystal microbalance, surface acoustic wave technique infrared or Raman microspectroscopy . Although these methods have been reported, their sensitivity in handling and time consuming process limits their applications.…”