Synthesis of 3D mesoporous samarium oxide hydrangea microspheres for enzyme-free sensor of hydrogen peroxide

A novel 3D mesoporous Sm2O3 hierarchical hydrangea microspheres sensor has been developed and investigated for highly sensitive electrochemical detection of hydrogen peroxide (H2O2). Their morphology and structure were observed by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) isotherms and the Barret-Joyner-Halenda (BJH) measurements. This stable non-enzymatic sensor was found to capable of implementing H2O2 detection in a wide linear range from 1 to 320 μM with a linear correlation coefficient (R) of 0.997. It presents an ultrahigh sensitivity of 20.5 μA mM−1, a remarkably low detection limit of ∼1 μM (signal/noise = 4), as well as a prompt response attaining 95% of steady current within 3 s. As such, the Sm2O3 hierarchical hydrangea microspheres are considered one of the remarkably prominent sensors for the detection of hydrogen peroxide in biological diagnosis, food and environmental monitoring.