A novel molecularly imprinted sensor for imidacloprid pesticide based on poly(levodopa) electro-polymerized/TiO2 nanoparticles composite

This research reports the first application of poly(levodopa) in the development of a molecularly imprinted sensor. A novel electrochemical sensor with high selectivity and sensitivity was developed for imidacloprid (IMD) determination based on an imprinted poly(levodopa) electro-polymerized on electrodeposited TiO2 nanoparticles (TiO(2)NPs) modified glassy carbon electrode (GCE). High affinity of IMD imprinted poly(levodopa) to IMD provided a very selective response of the electrode to IMD and electrodeposited TiO(2)NPs at the electrode surface resulted in the electrocatalytic reduction of IMD and consequently high sensitivity of the modified electrode. IMD imprinted poly(levodopa) electro-polymerized on TiO(2)NPs was well characterized by FT-IR, SEM, and EDX techniques. Sensor response to IMD was investigated by using square wave voltammetry (SWV), cyclic voltammetry (CV), and differential pulse voltammetry (DPV) techniques. The sensor showed a really vast linear range of 2-400M, completely low detection limit (LoD) of 0.3M, and limit of quantitation (LoQ) of 1M by SWV measurements that are very acceptable in comparison to other reported IMD sensors. Sensor application in real samples for IMD determination showed good applicability of the developed sensor. Response time is very short and the sensor showed suitable repeatability and stability after use several times.