Fabrication of novel electrochemical sensors based on modification with different polymorphs of MnO nanoparticles. Application to furosemide analysis in pharmaceutical and urine samples.

A novel MnO nanoparticles/chitosan-modified pencil graphite electrode (MnO NPs/CS/PGE) was constructed using two different MnO polymorphs (γ-MnO and ε-MnO nanoparticles). X-ray single phases of these two polymorphs were obtained by the comproportionation reaction between MnCl and KMnO (molar ratio of 5 : 1). The temperature of this reaction is the key factor governing the formation of the two polymorphs.