Sensors based on iron phthalocyanine films decorated with platinum nanoparticles and carbon rods for electrochemical detection of nitrites

Abstract

The iron phthalocyanine derivatives (FePc) are regarded as active layers of sensors. The films of iron phthalocyanines, viz. FePc, FePcF4, and FePcCl4 were deposited onto glassy carbon electrodes. Annealed film (a-FePc) were decorated with platinum nanoparticles (PtNPs) and carbon rods using facile metal organic chemical vapor deposition (MOCVD), resulting in a series of Pt/a-FePc heterostructures. The composition, distribution and sizes of PtNPs and carbon rods in the heterostructures were investigated. The electrochemical characteristics of the series of FePc, FePcF4, and FePcCl4 and Pt/a-FePc samples were determined in 0.1 M PBS solution using cyclic voltammetry (CV, 0.25–2.00 mM), amperometry (CA 0.5–30 μM), and impedance spectroscopy. The Pt/a-FePc heterostructures with a Pt content of 21–63 μM/cm2, which consisted of uniformly distributed PtNPs with a size of 9–12 nm and carbon rods up to 1 μm in length, demonstrated the excellent electron transfer characteristics Synergetic combination of the properties of 3 components (a-FePc, PtNPs or carbon rods) resulted in the improvement of the performance of Pt/a-FePc sensors. The Pt/a-FePc electrode demonstrated the lowest detection limit of 0.06 μM and high sensitivity to NO2−. This sensor had good selectivity in the presence of interfering analytes, repeatability and stability.