Detection of hydrogen peroxide (H₂O₂) using a colorimetric sensor based on cellulose nanowhiskers and silver nanoparticles

Hydrogen peroxide (H₂O₂) is an important compound for several industrial sectors, but it becomes harmful to human health under high concentrations. Thus, the development of simple, low cost and fast analytical methods capable to detect and monitor H₂O₂ is fundamentally important. In the present study, we report a simple route for synthesizing silver nanoparticles (AgNPs) in the presence of a nanostructured polysaccharide (cellulose nanowhiskers) to produce a hybrid material, which was employed as a colorimetric probe for H₂O₂ detection. Our results revealed that AgNPs tend to experience catalytic decomposition when exposed to H₂O₂, causing a decrease of AgNPs absorption band at 410 nm in accordance with H₂O₂ concentration. This decrease was linearly dependent on H₂O₂ concentration (in the ranges 0.01-30 μM and 60-600 μM), yielding limits of detection of 0.014 μM and 112 μM, respectively. The easy-to-interpret H₂O₂ sensor also proved to be suitable for real samples analysis even in the presence of other interfering substances.