The synthesis and characterization of 3D mesoporous CeO2 hollow spheres as a modifier for the simultaneous determination of amlodipine, hydrochlorothiazide and valsartan

Abstract

Herein, mesoporous CeO₂ hollow spheres (M-CeO₂-HSs) with a three-dimensional configuration were synthesized via a facile strategy. The morphology and structure of the three-dimensional M-CeO₂-HSs were characterized via XRD, SEM, and EDX. In order to demonstrate their practical application, the as-prepared M-CeO₂-HSs were applied as a modifier, which exhibited high catalytic activity for the simultaneous detection of amlodipine (AML), hydrochlorothiazide (HCTZ) and valsartan (VAL). Furthermore, a modified electrode was fabricated and investigated via electrochemical impedance spectroscopy (EIS). An unmodified GCE and the M-CeO₂-HS-modified glassy carbon electrode (M-CeO₂-HS/GCE) were utilized to assess their electrochemical behaviors towards AML, HCTZ and VAL. It was observed that the electrochemical responses of M-CeO₂-HS/GCE towards these analytes were remarkably enhanced. M-CeO₂-HS/GCE exhibited satisfactory responses for AML, HCTZ and VAL with detection limits of 7.9 nmol L⁻¹, 3.8 nmol L⁻¹ and 5.4 nmol L⁻¹ (S/N = 5), respectively. The diffusion coefficient (D) and heterogeneous rate constant (k_h) were detected for the oxidation of AML, HCTZ and VAL on the surface of the modified electrode. In addition, the analytical application of M-CeO₂-HS/GCE was investigated, which demonstrated acceptable results for the simultaneous detection of AML, HCTZ and VAL in real specimens.