MOF-Derived Porous CeO2−x/C Nanorods and Their Applications in Uric Acid Biosensor

Abstract

Selectivity is significant to the practical applications of electrochemical biosensors in clinical and diagnostic field. In this paper, porous CeO[Formula: see text]/C nanorods (NRs) derived from Ce-based metal organic framework (MOF) were synthesized and employed as substrate to construct uric acid biosensors with high sensitivity and selectivity at low working potential. The morphology, microstructures and elemental states of as-prepared samples were investigated by SEM, XRD, TEM and XPS systematically. It was found that a great amount of oxygen vacancies was introduced into the interstitial of CeO 2 and nonstoichiometric CeO 2 /C (CeO[Formula: see text]/C) nanorods based on Ce-MOF were formed under calcination in Ar atmosphere. The increased oxygen vacancies enabled the negatively shifting of the working potential towards H 2 O 2 detection for CeO[Formula: see text]/C nanorods, favoring the construction of biosensors based on the detection of H 2 O 2 . Uric biosensors based on CeO[Formula: see text]/C NRs exhibited a high sensitivity of 220.0[Formula: see text][Formula: see text]A[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text][Formula: see text][Formula: see text][Formula: see text]mM[Formula: see text] and a linear range from 50[Formula: see text][Formula: see text]M to 1000[Formula: see text][Formula: see text]M at working potential of [Formula: see text]0.4[Formula: see text]V versus SCE. It also exhibited superior selectivity toward interferents coexisting with uric acid in urine due to the low working potential.