Fabrication and characterization of a Layered Double Hydroxide based catalase biosensor and a catalytic sensor for hydrogen peroxide determination

An enzyme catalase biosensor was fabricated to determine hydrogen peroxide. The enzyme was cross-linked with [ZnIIAlIII (OH)2]+ NO3– Layered Double Hydroxide (LDH), which was glued on a glassy carbon (GC) electrode. The amperometric response to hydrogen peroxide was studied. A limit of detection (LOD) of about 0.20 mM and a good lifetime as high as 75 days were observed. A sensor with the same configuration, without the immobilized catalase enzyme and with LDH glued on (GC), was also realized. This non-enzymatic sensor also showed catalytic activity towards H2O2, exhibiting an amperometric response obviously much lower than that of the enzyme biosensor, with a LOD of about 1.0 mM. However, also the lifetime of this catalytic sensor was longer than 2 months after preparation.