Hollow Fe 2O 3 polyhedrons: One-pot synthesis and their use as electrochemical material for nitrite sensing

Abstract

In this paper, hollow hematite nano-polyhedrons (Fe-HNPs) were synthesized via a facile solution route. The abundance of high indexed facets was demonstrated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis. A new electrochemical biosensor for nitrite determination was then proposed by using the hematite hollow nanopolyhedron as the sensing layer. Electrochemical tests showed that the Fe-HNPs could act as efficient enzyme-like electron mediators for nitrite oxidation. As a result, the Fe 2O 3 modified biosensor exhibited excellent performance for the determination of nitrite with a response time of <10 s, linear range between 0.009 and 3 mM, and sensitivity as 19.83 μA mM −1. A high selectivity and long-term stability toward nitrite oxidation in the presence of glucose and l-ascorbic (AA) was also observed at their maximum physiological concentrations, which made this novel Fe 2O 3 nanomaterial bounded with high indexed facets promising for sensing applications in medicine, biotechnology and environmental chemistry.