Mussel-Inspired Magnetic Nanoflowers as an Effective Nanozyme and Antimicrobial Agent for Biosensing and Catalytic Reduction of Organic Dyes

Abstract

Mussel-inspired chemistry has been embodied as a method for acquiring multifunctional nanostructures. In this research, a novel mussel-inspired magnetic nanoflower was prepared through a mussel-inspired approach. Herein, magnetic PDA–Cu nanoflowers (NFs) were assembled via incorporating magnetic Fe 3 O 4 @SiO 2 –NH 2 core/shell nanoparticles (NPs) into mussel-inspired polydopamine (PDA) and copper phosphate as the organic and inorganic portions, respectively. Accordingly, the flower-like morphology of MNPs PDA–Cu NFs was characterized by scanning electron microscopy (SEM) images. X-ray diffraction (XRD) analysis confirmed the crystalline structure of magnetic nanoparticles (MNPs) and copper phosphate. Vibrating sample magnetometer (VSM) data revealed the superparamagnetic behavior of MNPs (40.5 emu/g) and MNPs PDA–Cu NFs (35.4 emu/g). Catalytic reduction of MNPs PDA–Cu NFs was evaluated through degradation of methylene blue (MB). The reduction of MB pursued the Langmuir–Hinshelwood mechanism and first-order kinetics, in which the apparent reduction rate K app of MB was higher than 1.44 min –1 and the dye degradation ability was 100%. MNPs PDA–Cu NFs also showed outstanding recyclability and reduction efficiency, for at least six cycles. Furthermore, the prepared MNPs PDA–Cu NFs demonstrated a peroxidase-like catalytic activity for catalyzing 3,3′,5,5′-tetramethylbenzidine (TMB) to a blue oxidized TMB (oxTMB) solution in the presence of H 2 O 2 . Antimicrobial assays for MNPs PDA–Cu and PDA–Cu NFs were conducted on both Gram-negative and Gram-positive bacteria. Moreover, we demonstrated how the existence of magnetic nanoparticles in PDA–Cu NFs influences the inhibition of an increasing zone. Based on the results, mussel-inspired magnetic nanoflowers appear to have great potential applications, including those relevant to biological, catalysis, and environmental research.

Magnetite Nanoparticle/Copper Phosphate Nanoflower Composites for Fenton-like Organic Dye Degradation

“…Figure reveals that the degradation of all MNPCuNFs was strongly dependent on where k abs is the observed rate constant of a pseudo-first-order reaction (min –1 ) and can be calculated from the slope of the line by plotting ln­( C / C 0 ) versus t (min –1 ). Plots of ln­( C / C 0 ) versus t (min –1 ) were linear with high correlation coefficients, R 2 > 0.9, establishing that the degradation rate of RhB by MNPCuNFs fits a pseudo-first-order kinetics model, which agrees with previous findings on the degradation of MB using polydopamine copper phosphate nanoflower . The removal of RhB using MNPCuNFs (bare MNP) and MNPCuNFs with surface-functionalized MNPs was investigated to determine their efficiencies.…”

“…Plots of ln(C/C 0 ) versus t (min −1 ) were linear with high correlation coefficients, R 2 > 0.9, establishing that the degradation rate of RhB by MNPCuNFs fits a pseudo-first-order kinetics model, which agrees with previous findings on the degradation of MB using polydopamine copper phosphate nanoflower. 24 The removal of RhB using MNPCuNFs (bare MNP) and MNPCuNFs with surface-functionalized MNPs was investigated to determine their efficiencies. At 50 °C, >90% of RhB was removed by MNPCuNFs (k abs = 0.2736) within 10 min, while <60% (k abs < 0.13) was degraded for MNPCuNFs with surface-functionalized MNPs (Figure 4a), which can be attributed to the Fenton active sites on the bare MNPs.…”

Micro‐Bio‐Chemo‐Mechanical‐Systems: Micromotors, Microfluidics, and Nanozymes for Biomedical Applications

“…Magnetic nanozymes, such as mussel‐inspired nanoflower (PDA‐Cu NFs) are considered as antibacterial agents for biosensing applications. [ 130 ] Another group reported laccase‐like active magnetic nanozyme which can be used for efficient removal of toxic phenolic pollutant like o ‐phenylenediamine (OPD). [ 131 ] Optically active plasmonic nanozymes (AuNPs) exhibits enhanced peroxidase‐mimicking activity.…”

A Cu(ii) complex supported on Fe3O4@SiO2 as a magnetic heterogeneous catalyst for the reduction of environmental pollutants

“…Moreover, the catalytic activity of the synthesized CM@SS-BBTU-Cu(II) catalyst was compared with those of some heterogeneous catalysts 33,[119][120][121][122][123][124][125][126][127][128][129][130] recently used in the reduction of MB in order to show the advantage of our catalyst system (Table 3). The results showed that CM@SS-BBTU-Cu(II) was better than previously reported catalysts in terms of reaction time.…”