# Application of Molecularly Imprinted Polymers in the Analysis of Waters and Wastewaters
## 5 Application of MIPs for the Detection of Different Classes of Contaminants
### Pesticides
#### 5.3.1 Insecticides
As methyl-parathion is electroactive, MIP-based electrochemical sensors prepared using both electro- and bulk polymerization was applied for its detection [112]. Electropolymerized p-aminothiophenal was used as functional monomer on GCE modified with gold nanoparticles coated with carbon nanotubes. Linear sweep voltammetry results showed a linear range 0.38-4.2 nM and 4.2-42 nM, with a limit of detection of 0.30 nM for spiked distilled and tap water samples. Modified carbon paste electrodes (CPE) were applied for the detection of parathion [113] and diazimon [109], where the MIPs were synthesized by the bulk polymerization method and utilizing MAA as the functional monomer. The results for parathion detection in tap, river, and lake water showed LOD 0.5 nM and linear range 1.7 \(\times\) 10\({}^{2}\)-9.0 \(\times\) 10\({}^{2}\) nM by using SWV after multiwalled carbon nanotubes (MWNTs) modification. Detection of diazimon in tap and river water sample was performed successfully with LOD 0.13 nM and linear range 0.5-1.0 \(\times\) 10\({}^{3}\) nM. Metal organic frameworks (MOFs) connected by self-assembly with transition metal ions/clusters and organic ligands have seen a rise in scientific interest in recent years, as they led to improving the response characteristics in the detection of some pesticides. A disposable molecularly imprinted electrochemical sensor was developed for phosalone (PAS), employing home-made carbon paste microelectrode (CPME) modified with a Zr-based metal\(-\)organic framework catalyst (Pt\(-\)UiO\(-\)66) and mesoporous structured conductive molecularly imprinted polymer. The MIP was prepared using the sol-gel method with 3-aminopropyltriethoxysilane (APTES) as the functional monomer, and UiO-66 was mixed with Pt nanoparticles as modifier as shown in Figure 6. The sensors response for lake water samples showed limit of detection 0.078 nM and linear range 0.50-2.0 \(\times\) 10\({}^{4}\) nM [119]. Cyperethrin (CYP) is a pyrethroid insecticide that is more effective and less harmful than organophosphates in terms of insecticidal activity. A surface-enhanced Raman spectroscopy (SERS)-active substrates were developed using Au nanoparticles (NPs) coated with a layer of polymer and followed by imprinting with a pesticide--Cypermethrin. The captured molecules situated in between the areas of high electromagnetic field formed by plasmonic Au NPs result in an effect of SERS. The results showed that Au NP/MIP was competent to detect both similar molecules despite the imprint being made only by cypermethrin. Nevertheless, Au NP/MIP has a limited number of imprinted cavities that resulted in sensing only low concentrations of a pesticide solution. Au NP/MIP is, thus, a specific design for detecting analogous molecules similar to its template structure [120]. The optical microscope of the spectrometer was set at 50 magnification and the He-Ne Raman lasers used have a diameter of 1 m; laser excitation wavelengths of 633 and 785 nm with gratings at 1800 and 1200 lines/nm, respectively, were used. Cyperethrin in spiked wastewater samples was detected employing an MIP sensor based on the polymerization of phenol as a functional monomer on glassy carbon electrode modified with core-shell type nanoparticles (Fe@AuNPs), including two-dimensional hexagonal boron nitride (2D-hBN) nanosheets [107]. The produced nanocomposites have good sensitivity and selectivity in the detection of CYP with LOD 3.0 \(\times\) 10\({}^{5}\) nM and linear range 1.0 \(\times\) 10\({}^{-3}\)-10 nM. Another hybrid electrochemical sensor for sensitive detection of cypermethrin (CYP) was also reported. Firstly, Ag and N co-doped zinc oxide (Ag-N@ZnO) was produced by the sol-gel method, and then Ag-N@ZnO was ultrasonically supported on activated carbon prepared from coconut husk (Ag-N@ZnO/CHAC).