Fabrication and characterization of CuO nano-needles from thermal decomposition of Cu(II) metal complex: Fluorometric detection of antibiotics, antioxidant, and antimicrobial activities

Abstract

In the present study, CuO NPs and CuO nano-needles were synthesized using thermal decomposition of Cu(II) complex derived from 2-(4-(trifluoromethoxy)phenylimino)methyl)-6-methoxyphenol (TMPM6MOP) and characterized by UV–vis DRS, PL, FTIR, XRD, and SEM. The monoclinic crystalline nature of the CuO NPs and CuO needles was illustrated by the XRD. The average size of the CuO NPs (30 nm) and CuO needles (diameter 10 nm, length 250 nm) were estimated from XRD and SEM. The prepared CuO needles were used as a fluorescent sensor for the selective and sensitive detection of ciprofloxacin (Cipro) among various antibiotics at diverse pH (4.0–9.0) conditions and the optimized pH = 5.0. The response of Cipro using the CuO needles was linear over the range from 10 to 100 µM L–1. This sensor showed the lowest limit of detection of 0.21 nM and was much lower than the other antibiotic sensors. In addition, the sensor is highly sensitive, selective, and durable in the presence of a range of potentially interfering fluorometric active compounds due to the large surface area and positive surface charge of the CuO needles. Moreover, antimicrobial activities and antioxidant activities were investigated to evaluate the biological potential of the CuO NPs and CuO needles.