Synthesis, characterization, and interaction studies of uncapped, PVP, and CTAB capped CuO nanorods with aldicarb and chlorpyrifos

Uncapped copper oxide nanorods (CuOnrs), capped with cetyltrimethylammonium bromide (CTAB-CuOnrs), and polyvinyl pyrrolidine (PVP-CuOnrs) were utilized for the interaction study of the carbamate (Aldicarb (A.D.)) and organophosphate (Chlorpyrifos (C.P.)) pesticides. These nanorods were synthesized using the co-precipitation method, followed by calcination at 350 C for 2 hr. X-ray diffraction study confirmed the monoclinic structure of the CuOnrs without any impurities with average crystallite size in the range of 10-12 nm. Field emission scanning and transmission electron microscopy (FE-SEM & TEM) studies confirmed the nanocrystalline structure of CuOnrs, CTAB-CuOnrs, and PVP-CuOnrs having rod-like structures. The contact angle study showed the hydrophilic nature of the uncapped CuOnrs and PVP-CuOnrs with a contact angle of 51 & 57 , respectively. While CTAB-CuOnrs exhibited hydrophobic nature with a contact angle of more than 90 . Interaction study of CuOnrs, CTAB-CuOnrs, and PVP-CuOnrs with A.D. and C.P was conducted using U.V.- vis absorption study (in the 250 - 400 nm region). Uncapped CuOnrs have shown the specific detection with A.D., while CTAB-CuOnrs have shown with C.P. without using any bio-recognition elements. PVP-CuOnrs did not show systematic change with both pesticides confirming the capping agent-dependent specific interaction of the pesticides.