title: Hydrogen peroxide displacing DNA from nanoceria: mechanism and detection of glucose in serum.
abstract: Hydrogen peroxide (H2O2) is a key molecule in biology. As a byproduct of many enzymatic reactions, H2O2 is also a popular biosensor target. Recently, interfacing H2O2 with inorganic nanoparticles has produced a number of nanozymes showing peroxidase or catalase activities. CeO2 nanoparticle (nanoceria) is a classical nanozyme. Herein, a fluorescently labeled DNA is used as a probe, and H2O2 can readily displace adsorbed DNA from nanoceria, resulting in over 20-fold fluorescence enhancement. The displacement mechanism instead of oxidative DNA cleavage is confirmed by denaturing gel electrophoresis and surface group pKa measurement. This system can sensitively detect H2O2 down to 130 nM (4.4 parts-per-billion). When coupled with glucose oxidase, glucose is detected down to 8.9 μM in buffer. Detection in serum is also achieved with results comparable with that from a commercial glucose meter. With an understanding of the ligand role of H2O2, new applications in rational materials design, sensor development, and drug delivery can be further exploited.
authors.affiliation: Department of Chemistry, Waterloo Institute for Nanotechnology , Waterloo, Ontario, Canada N2L 3G1.
authors.forename: Biwu
authors.initials: B
authors.lastname: Liu
authors.forename: Ziyi
authors.initials: Z
authors.lastname: Sun
authors.forename: Po-Jung Jimmy
authors.initials: PJ
authors.lastname: Huang
authors.forename: Juewen
authors.initials: J
authors.lastname: Liu
mesh_terms: D015374:Biosensing Techniques; D002563:Cerium / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D005947:Glucose / Q000032:analysis*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration
chemical_list: D002563:Cerium; C030583:ceric oxide; D004247:DNA; D006861:Hydrogen Peroxide; D005947:Glucose