Functional alkoxysilane mediated controlled synthesis of Prussian blue nanoparticles, enabling silica alginate bead development; nanomaterial for selective electrochemical sensing

We report herein the controlled synthetic strategy for Prussian blue nanoparticles (PBNPs) formation justifying the role of functional alkoxysilanes, [2-(3,4-Epoxycyclohexyl)ethyl]trimethoxysilane (EETMSi) in the presence of tetrahydrofuran hydroperoxide (THF-HPO) with following major findings: (i) significant change in nanogeometry from 40 to 8 nm by addition of EETMSi and (ii) allowed fabrication of PBNPs encapsulated silica-alginate beads. As made nanoparticles were characterized by UV-Vis spectroscopy, TEM, FT-IR, and SEM. Size dependent electrochemical behavior of three different PBNPs i.e. PBNPs-1 (26 nm), PBNPs-2 (17 nm) and PBNPs-3 (8 nm) was recorded based on cyclic voltammetry. Apart from unprecedented size-dependent properties, as made PBNPs-3 display excellent peroxidase mimetic activity with Km value to the order of ∼0.9 mM. In addition, EETMSi also allows to cast Prussian blue film and simultaneously enable the formation of silica-alginate beads with controlled pores size perfectly suitable for encapsulating these nanoparticles which allocate selective electrochemical oxidation of Pyrogallol (Py) at 0.3 V vs. Ag/AgCl.