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, CeO /CePO nanocrystal were synthesized in one-step, which integrated the enzyme activities of CeO and CePO , as well as the optical property of CePO together. Taking H O as analyte model, utilizing the catalase oxidization activity of CeO /CePO , TMB molecule can be oxidized, leading to the increased absorption intensity of 652 nm, realizing the colorimetric assay of H O . On the other hand, using the fluorescence of CeO /CePO at 338 nm as output signal, which can be quenched by H O since Ce ions were oxidized into Ce , realizing H O fluorescence detection. Compared with the single-signal probe, CeO /CePO provides two sensing modes of fluorescence and colorimetry for H O discrimination to obtain different test results, which can be mutually verified and effectively improve the detection accuracy.