Multifunctional maca extract coated CuO nanoparticles with antimicrobial and dopamine sensing activities: A dual electrochemical – Smartphone colorimetric detection system

Abstract

Current trends and future innovative issues focus on the development of smart multifunctional bio-nanostructures. In this study, novel maca extract-coated CuO nanoparticles (MaE-CuO NPs) were prepared using a green and facile sonication method. Multifunctional MaE-CuO NPs were characterized by different techniques, such as Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), High Resolution Transmission Electron Microscopy (HRTEM), Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET) techniques. According to the results, we proved that the sonosynthesized MaE-CuO NPs had a uniform spherical shape with an average diameter range of ∼ 10 nm, while the surface area was 344.645 m2/g. The preservative performance of the antimicrobial MaE-CuO NPs was investigated to evaluate the biological activity of the nanostructure against Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli (E. coli), Candida albicans (C. albicans), and Aspergillus brasiliensis (A. brasiliensis). Furthermore, the MaE-CuO NPs-based non-enzymatic electrochemical and smartphone colorimetric biosensor detected dopamine in the concentration range from 0.625 to 5 µM with a high sensitivity of 667 µA μM−1cm−2 and a low limit of detection (LOD) value of 16.9 nM. Consequently, we proved that the obtained nanoformulations are promising antimicrobials agents and colorimetric/electrochemical dual-mode biosensors.