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Hybrid nanomaterials have outstanding properties that are superior to the corresponding constituents working alone. This work reports on the electroanalysis of a hybrid material‐decorated screen‐printed carbon electrode (SPCE) that consists of iron nanoparticles supported at multi‐wall carbon nanotubes (MWCNT), coated with graphene layers, named Fe@G‐MWCNT. Electrochemical and morphological characterizations were carried out by cyclic voltammetry, electrochemical impedance spectroscopy and high‐resolution transmission electron microscopy, respectively. After optimizing the amount of hybrid material to be drop casted at the SPCE, its electrochemical activation in sulphuric acid produced an enhanced response. The resultant electrochemically reduced Fe@G‐MWCNT‐e‐modified electrode exhibited a diffusion‐controlled redox process with an enhanced heterogeneous electron‐transfer rate constant of 3.21×10−2 cm⋅s−1, which was superior to that from the MWCNT counterpart. However, it was slightly lower than that from a Fe‐MWCNT‐decorated electrode. The graphene coating limited slightly the electron‐transfer process, but works as a protective layer that prevent the loss of Fe catalytic activity. The electrochemical response of the hybrid with graphene coated Fe decreased only a 24.3 % after one week, respect to 51.9 % of the uncoated one. In addition, the hybrid material‐modified electrode exhibited electrocatalytic activity towards the reduction of H2O2 in a linear range of 0.5 mM to 9.8 mM, with sensitivity of 7.97 μA⋅mM−1 and LOD of 0.65 mM, thereby opening an avenue for the development of more specific and highly sensitive Fe@G‐MWCNT hybrid‐based (bio) sensors.

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Nanoengineering biosensors have become more precise and sophisticated, raising the demand for highly sensitive architectures to monitor target analytes at extremely low concentrations often required, for example, for biomedical applications. We review recent advances in functional nanomaterials, mainly based on novel organic-inorganic hybrids with enhanced electro-physicochemical properties toward fulfilling this need. In this context, this review classifies some recently engineered organic-inorganic metallic-, silicon-, carbonaceous-, and polymeric-nanomaterials and describes their structural properties and features when incorporated into biosensing systems. It further shows the latest advances in ultrasensitive electrochemical biosensors engineered from such innovative nanomaterials highlighting their advantages concerning the concomitant constituents acting alone, fulfilling the gap from other reviews in the literature. Finally, it mentioned the limitations and opportunities of hybrid nanomaterials from the point of view of current nanotechnology and future considerations for advancing their use in enhanced electrochemical platforms.

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