A novel amperometric hydrogen peroxide biosensor based on immobilization of hemoglobin in linoleic acid monolayer by Langmuir–Blodgett technique

In this paper, we reported a novel amperometric hydrogen peroxide (H2O2) biosensor for the first time based on immobilization of hemoglobin (Hb) incorporated in linoleic acid (LA) on gold electrode surface by Langmuir–Blodgett (LB) technique. Atomic force microscopy image of Hb–LA LB film indicated that Hb molecules existed in LA layer with a well-ordered and compact form. The electrode modified with Hb–LA LB film displayed a couple of stable and well-defined redox peaks with a peak-to-peak separation of 80 mV, indicating that the electron transfer between Hb and electrode was accelerated by Hb incorporated in LA monolayer. This modified electrode showed the electrochemical activity to reduction of H2O2 without aid of any electron mediator. Under the optimal conditions, a linear dependence of the catalytic current versus H2O2 concentration was obtained in the range of 2.0–100.0 μM with a detection limit of 1.2 μM.