One-Pot Synthesis of Ce-Based Nanocomposites for Fluorescence and Colorimetric Dual-Mode Sensing Platform Construction.

Ce-based nanomaterials have been widely studied as catalyst for their unique electronic structure, but there are few reports on the combination of cerium catalytic activity and photoluminescence performance. In this paper, by adjusting the molar ratio of Ce/P, CeO2/CePO4 nanocrystal were synthesized in one-step, which integrated the enzyme activities of CeO2 and CePO4, as well as the optical property of CePO4 together. Taking H2O2 as analyte model, utilizing the catalase oxidization activity of CeO2/CePO4, TMB molecule can be oxidized, leading to the increased absorption intensity of 652 nm, realizing the colorimetric assay of H2O2. On the other hand, using the fluorescence of CeO2/CePO4 at 338 nm as output signal, which can be quenched by H2O2 since Ce3+ ions were oxidized into Ce4+, realizing H2O2 fluorescence detection. Compared with the single-signal probe, CeO2/CePO4 provides two sensing modes of fluorescence and colorimetry for H2O2 discrimination to obtain different test results, which can be mutually verified and effectively improve the detection accuracy. [ABSTRACT FROM AUTHOR]