Spherical MnFe2O4 and MnFe2O4@YPO4:5 Eu3+ magnetic nanoparticles have been prepared by co‐precipitation method. Crystal structure, morphology, elemental composition and surface structure were characterised by X‐ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and Infra‐red spectroscopy (IR). Their calculated average crystallite sizes are found to be 28 and 35 nm respectively. And the prepared nanoparticles are having spherical morphology. The composite bond formation between MnFe2O4 and YPO4:5 Eu3+ is confirmed by more intense bending vibrations of PO43− group for hybrid nanoparticles. The magnetization of hybrid nanoparticles shows magnetization per gram of MnFe2O4, Ms= 34.355 emu/g with negligible coercivity indicating superparamagnetic behaviour. Prepared magnetic nanoparticles achieve hyperthermia temperature (42 °C to 47 °C) under AC magnetic field indicating potential material for biological application. The prepared nanoparticles are showing red luminescence peaks at 615 nm and 702 nm, which are included in the range of biological window.

The size of the particles of CaWO4:Dy3+ increases with the addition of NH4Cl/KCl electrolyte and enhances its luminescence.

Environmentally benign, stable quantum dot size spherical Cu particles with an average size of ∼ 4.5 nm, as measured via transmission electron microscope, were coherently tailored exploiting renewable ethno‐pharmacological Oxalis corniculata plant extract as both reducing plus capping agent. The reliable green aqueous synthesis approach completely excluded the usage of inert atmosphere and harmful chemicals including organic solvents. The ensuing cost effective Cu nanoparticles exhibited excellent intrinsic peroxidase like activity and superior nanozyme behaviour compare to earlier reports with Km value of 0.01426 M and rmax equal to 0.1399 Mmin−1 toward the oxidation of peroxidase substrate H2O2 in presence of o‐phenylenediamine, a paradigm reaction. Significantly, the as‐prepared Cu particles have been proven to be a novel catalyst for feasible selective aqueous phase conversion of fructose to levulinic acid with a maximum yield of ∼ 22.38% at 90°C in the absenteeism of prominent side product(s), auxiliaries and high temperature reaction condition. Lewis acid property and large surface area of the generated nanoscale particles attributed to their excellent catalytic potential introducing a new avenue in the continuous demand for better sensing, biomedical applications and cleaner energy production.

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