Self-assembled Pt screen printed electrodes with a novel peroxidase Panicum maximum and zinc oxide nanoparticles for H₂O₂ detection

Herein, we report the construction of a specific biosensor to detect hydrogen peroxide (H₂O₂), an important molecule in many fields, including environmental protection and clinical control. The convergence of electronic properties of zinc oxide nanoparticles (ZnONPs) synthesized into nanoreactors and the biological recognition of novel Guinea Grass Peroxidase (GGP) was achieved. Using a low cost and simple layer-by-layer method this work demonstrates the importance of using ultra-small semiconductor nanoparticles between electrode active surface and biomolecules in a biosensor. Spectroscopic and scattering techniques were used to characterize ZnONPs, potassium ferro/ferri cyanide couples and cyclic voltammetry were used for electro-analytical studies. The platinum electrode modified with less than 5 nm ZnONPs, glutaraldehyde as linker agent and GGPs as a biological recognition element exhibited excellent catalytic activity towards H₂O₂ reduction with a linear response, a detection limit of 84 mM, and high specificity amongother types of peroxidases. This new biosensor is very attractive not only by its effectiveness but also by its portability and impact in several fields of science and industry.