Functionalized fullerene (C 60 ) as a potential nanomediator in the fabrication of highly sensitive biosensors

Fullerenes in Electrochemical Catalytic and Affinity Biosensing: A Review

“…It has been shown that exohedrally functionalized fullerenes bearing organic or organometallic functional groups attached to the exterior of the carbon cage are more accessible than endohedral metallofullerenes. Numerous research efforts support the notion that exohedral functionalized fullerene can be a suitable nanomaterial able to improve the sensitivity, selectivity, and reproducibility of electrochemical biosensors [21]. Different biomolecules or organic ligands can be immobilized onto the shell of fullerenes by adsorption or covalent attachment.…”

“…The incorporation of fullerenes for preparing electrochemical biosensors has led to the development of a variety of fullerene functionalization methods, profiting the high surface area-to-volume ratio of these nanomaterials. Amine and carboxylic acid functional groups have been widely incorporated into fullerenes to allow them to easily react with biomolecules [21]. From the viewpoint of fullerene chemistry, functionalized fullerene can be categorized into two basic types: exohedral, where substituents are intercalated outside the cage, and endohedral, where molecules are trapped inside the cage.…”

“…Amine and carboxylic acid functional groups have been widely incorporated into fullerenes to allow them to easily react with biomolecules [21]. From the viewpoint of fullerene chemistry, functionalized fullerene can be categorized into two basic types: exohedral, where substituents are intercalated outside the cage, and endohedral, where molecules are trapped inside the cage.…”

“…Moreover, C 60 owned its inner redox activity [15], being able to act as an electron acceptor with a dual nature of electrophilic and nucleophilic characteristics, which has led to significant interest from researchers to investigate the possibilities of using this material as a mediator in biosensing devices [4,15,20]. Fullerene is used as a mediator between the recognition site and the electrode in electrochemical biosensors to enhance the rate of electron transfer produced due to the biocatalytic or biochemical reaction of the analyte in contact with the biological element at the recognition site (see Figure 2) [21]. Due to the ability of lowering the potential of electro-reduction of many different redox substrates and increasing the C 2017, 3, 21 3 of 17 reaction rates, fullerenes have been used to improve the sensitivity and selectivity of the resulting biosensors [8].…”

“…This problem can be overcome by C 60 functionalization though the covalent binding of functional groups such as carboxyl, hydroxyl, amine groups, etc. [4,7,19,21]. For example, hydroxyl fullerenes (HFs) are water soluble fullerene derivatives with a formula of C 60 (OH) n (n = 18−24).…”