Effect of temperature-controlled poly(diallyldimethylammonium chloride) on morphology of self-assembled Prussian Blue electrode and its high detection sensitivity of hydrogen peroxide

Based on positively charged poly(diallyldimethylammonium chloride) (PDDA) layer providing nucleation sites for the growth of PB via self-assemble process, regular Prussian Blue (PB) nanocubes was obtained on the Pt electrode by simply adjusting adsorption temperatures of PDDA. Electrochemical impedance spectroscopy (EIS) was applied to study the coverage and electrical resistance of PDDA on the electrode with different adsorbed temperatures. The evolutions of PB morphology with temperature-controlled PDDA were characterized by field emission scanning electron microscope (FESEM). Investigation on the electrochemical property of the modified electrodes was also carried out using Chronoamperometry. Control of temperature could optimize the charge density distribution of PDDA on electrode and further construct the regular growth of PB crystal. At the PDDA adsorbed temperature of 30 °C, the as-fabricated PB modified electrode showed an excellent sensitivity to hydrogen peroxide response of about 1179.6 mA M^-1 cm^-2, a rapid response time within 2 s, and a wide linear range up to 600 μM H₂O₂. In addition, the sensor exhibited good reproducibility and stability.