High-sensitive molecularly imprinted sensor with multilayer nanocomposite for 2,6-dichlorophenol detection based on surface-enhanced Raman scattering.

This study describes the preparation of a novel multilayer sensor based on molecularly imprinted polymers (MIPs) for the detection of trace-level chlorophenols by surface-enhanced Raman scattering (SERS). Composites of SiO2/reduced graphene oxide/gold (SiO2/rGO/Au, SGA) are chosen as the SERS substrates. The fabricated composites are able to enhance the SERS sensitivity, and the addition of MIPs improves the selectivity of traditional SERS substrates. Furthermore, the sensor's detection sensitivity and selectivity are improved by including two functional monomers, namely methacrylic acid (MAA) and acrylamide (AM) containing different functional groups. Finally, in to more effectively balance the selectivity of MIPs shell and the sensitivity of SERS detection, the prepared substrates are surface-modified with polydopamine (pDA) and prepared by atom transfer radical polymerization (ATRP). It is confirmed that the prepared SGA-MIPs exhibits relatively good sensitivity and selectivity in the detection of chlorophenols. Importantly, all the investigations are conducted in environmentally friendly aqueous solution, which enables scaling-up without causing pollution.