Architecture of Ba/alginate/dextran stabilized Au, Fe3O4, TiO2 & silica nanoparticles gels and their applications for reduction of 4-nitrophenol and glucose sensing

An innovative method is presented to produce anisotropically ordered capillaries and small pores by dissipative convective process followed by simple freezing in liquid nitrogen of Ba/alginate/dextran hydrogels with and without nanoparticles. Magnetite, gold, silica or titanium dioxide nanoparticles were encapsulated safely into the gels with protecting their stability and microstructures. Mechanical strength and rheological studies of the gels were also investigated. Ba/alginate/dextran/Au composite gel has shown excellent catalytic activity for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in presence of NaBH4 with a rate constant of 6.85 × 10− 3 min− 1. Ba/Alg/Dex/Au-GCE exhibits non-enzymatic electrocatalytic oxidation of glucose with linear range from 1 mM to 10 mM (r = 0.998) and the detection limit to 63 μM at a signal-to-noise ratio of 3.