Catalysis Induced by Platinum and Palladium Nanoparticles

3 Electrocatalytic Activity of Gold Nanoparticles Used as Modifiers of Eiectrotransducer Surfaces 

Another application of metal nanoparticles in electrochemical detection of DNA is their incorporation with composites used as electrode surface modifiers. Even though these modified electrodes can show higher background signals than the unmodified electrodes, the incorporation of Au-NPs can be used to promote selective immobilization spots to well-oriented DNA detection probes. 

Despite the high cost of this metal in the bulk state, the subsequent saving that reducing the metal size implies placed platinum nanoparticles (Pt-NPs) in the centre of attention of scientists due to their ability to be used as catalyst for many industrial processes [13]. 

Pt-NPs are used as catalysts for electrochemical hydrogen peroxide (H2O2) detection, where they act as modifiers of the electrode surface and electrocatalyze the oxidation of H2O2 observed by a lower oxidation peak potential when compared with the bulk platinum electrode [30]. As the H2O2 is a product of many enzymatic reactions, this electrode has a vast potential application as an electrochemical biosensor for many substances [15]. 

Pt-NPs have also been used as catalysts in gas sensors like nitric oxide (NO) sensor making use of the electrocatal3d ic effect in the oxidation of this specie [31]. In conjugation with carbon nanotubes (CNTs) and glutaraldehyde, Pt-NPs also allowed the development of a carbon-based electrode as a sensor for glucose, in a similar system as one of the reported H2O2 sensors [13]. 

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