Fabrication of selective and sensitive chemical sensor development based on flower-flake La2ZnO4 nanocomposite for effective non-enzymatic sensing of hydrogen peroxide by electrochemical method

Abstract

In this study, hydrogen peroxide sensor based on electrochemical approach using flower-flake La2ZnO4 (FF) was reported. Hydrogen peroxide is an oxidative stress indicator that could be a signal to terminal diseases such as cancer, aging, traumatic brain damage, ischemia/reperfusion malfunction and memory damage. Due to this medical importance, an accurate and cheap method of its detection is reported in this study based on electrochemical approach using La2ZnO4. La2ZnO4 FF was prepared by wet chemical method and well characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infra-red (FTIR) spectrophotometry, ultraviolet (UV) spectrophotometry and electrochemical impedance spectroscopy (EIS). Differential pulse voltametric method was employed to detect H2O2 on the surface of La2ZnO4 modified glassy carbon electrode (GCE). La2ZnO4 FF modified GCE displayed good current response and electro-catalytic property towards hydrogen peroxide compared to bare GCE. The La2ZnO4 FF coated GCE had limit of detection (0.04 µM), high sensitivity (25.0 µAµM−1cm−2) and long linear range (3.0 µM to 85.0 µM). Results of recovery studies for real samples of tap water, well water, sea water industrial effluent, milk, yoghurt and human urine were 94%, 93%, 98%, 91%, 97%, 108%, and 110% respectively. These values show practical usability of La2ZnO4 in real biological and environmental samples.