Objective(s): High levels of hydrogen peroxide (H۲O۲) induce oxidative stress in physiological environments. Elevation of H۲O۲ levels in semen can be a reason for male infertility, by causing protein and enzyme denaturation, lipid peroxidation, and DNA damage. Oxidative stress can affect sperm features, such as viability, motility, and fertilization potential. Although nanozymes are widely used to detect H۲O۲ using different techniques, monitoring of H۲O۲ in physiological fluids remains a challenge that has not been studied extensively. We report on a non-enzymatic paper strip based on γ-Fe۲O۳@Prussian blue nanoparticles (γ-Fe۲O۳@PB NPs) and their performance for H۲O۲ detection in buffer and seminal plasma. Materials and Methods: γ-Fe۲O۳ NPs were synthesized using chemical coprecipitation method and were then coated with PB. γ-Fe۲O۳@PB NPs were characterized using ultraviolet-visible spectroscopy (UV-vis), dynamic light scattering (DLS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results confirmed formation of relatively monodisperse and approximately ۷۱ nm γ-Fe۲O۳@PB NPs. The peroxidase-like activities of γ-Fe۲O۳ NPs and γ-Fe۲O۳@PB NPs were measured using UV-visible spectroscopy. Results: The results demonstrated that the catalytic activity of γ-Fe۲O۳@PB NPs was higher than that of γ-Fe ۲ O۳ NPs. The concentrations of γ-Fe۲O۳@PB NPs and TMB, immobilized on paper strips, were optimized. The detection limit of the constructed lateral flow assays (LFA) for H۲O۲ in acetate buffer was ۵۰.۰ µM. Citric acid and ascorbic acid, as common components in semen, showed interference with the performance of paper strips. The γ-Fe۲O۳@PB NPs-based paper strip could detect H۲O۲ spiked in human seminal plasma in ۲۰ min with a detection limit of ۷۵۰.۰ µM. Conclusion: The colorimetric detection of H۲O۲ on paper strips was successful and quantification of the results was possible with the help of a cell phone, which makes it a breakthrough in quantitative rapid tests.
