Molecularly imprinted polymers to detect profenofos and carbofuran selectively with QCM sensors

Two different molecularly imprinted polymers (MIP) were designed to selectively bind the insecticides carbofuran (CBF) and profenofos (PFF). CBF-MIP are based on methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a crosslinker, and azobisisobutyronitrile (AIBN) as an initiator. The PFF-MIP comprised of polyurethane based on poly (4-vinylphenol) (PVP), and diphenyl methane-4,4′-di-isocyanate (DPDI) as functional monomers, phloroglucinol (PG) as the cross-linker, and diphenylmethane (DPM) as the porogen. For sensor measurement, MIPs were spin-coated onto one electrode pair of a dual-electrode QCM, while the second pair was spin-coated with NIPs. Fourier transform infrared (FT-IR) spectroscopy confirms successful template removal from the polymer matrix. The resulting CBF- and PFF-MIP coated onto quartz crystal microbalances (QCMs) lead to pesticide QCM sensors revealing the following analytical characteristics, respectively: dynamic detection range of 0.5–1000 μM for CBF-MIP and 10–1000 μM for PFF-MIP. In both cases, the MIP exhibit roughly ten times higher sensor signals, than the corresponding non-imprinted polymers (NIP).