Remarkably selective metallized-carbon amperometric biosensors

The use of metallized carbon transducers results in remarkably selective amperometric biosensors. Such focus on the transducer eliminates major electroactive interferences in the first place, and hence circumvents the need for anti-interference layers. The remarkable selectivity of metal-dispersed carbons is attributed to their strong, preferential, electrocatalytic action towards the detection of the enzymatically-liberated hydrogen peroxide and reduced nicotinamide cofactor (NADH). Such activity allows tuning of the operating potential to the region (+ 0.1 to −0.2 V) where unwanted reactions do not occur. This article reviews the development of metallized-carbon biosensors, with particular emphasis on metallized carbon-paste enzyme electrodes, miniaturized devices based on electrochemical deposition of the metal/enzyme layer and metal-dispersed sensor strips.