Background:
Cerium oxide nanoparticles (nanoceria) are efficient free-radical scavengers
due to their dual valence state and thus exhibit optical and catalytic properties. Therefore, the main
purpose of this work was to understand the peroxidase mimic activity of polymer-stabilized
nanoceria for enzyme-less H2O2 sensing by fluorescence spectrometer.
Objective:
This research revealed the development of fluorescence hydrogen peroxide nanosensor
based on the peroxidase-like activity of polyacrylic acid stabilized nanoceria (PAA-CeO2 Nps).
Methods:
PAA-CeO2 Nps were synthesized by simple cross-linking reaction at a low temperature
and characterized by XRD, SEM, Zeta potential, TGA, FT-IR and UV-VIS spectroscopic analysis.
H2O2 sensing was performed by a fluorescence spectrometer.
Results::
The synthesized polymer nanocomposite was characterized by XRD, SEM, TGA, FT-IR
and UV-VIS spectroscopic analysis. The XRD diffraction patterns confirmed the polycrystalline
nature and SEM micrograph showed nanoparticles having hexagonal symmetry and crystallite size of
32 nm. The broad peak of Ce–O bond appeared at 508 cm-1. UV-VIS measurements revealed a welldefined
absorbance peak around 315 nm and an optical band-gap of 3.17 eV. As synthesized PAACeO2
Nps effectively catalysed the decomposition of hydrogen peroxide (H2O2) into hydroxyl radicals.
Then terephthalic acid was oxidized by hydroxyl radical to form a highly fluorescent product.
Under optimized conditions, the linear range for determination of hydrogen peroxide was 0.01 - 0.2
mM with a limit of detection (LOD) of 1.2 μM.
Conclusion:
The proposed method is ideally suited for the sensing of H2O2 at a low cost and this
detection system enabled the sensing of analytes (sugars), which can enzymatically generate hydrogen
peroxide.
Cerium oxide nanoparticles at the nano-bio interface: size-dependent cellular uptake