Modification of carbon nanotubes with redox hydrogel: Improvement of amperometric sensing sensitivity for redox enzymes

Electrochemical Biosensing Based on Carbon Nanotubes

“…The incorporation of SWCNTs, modified with glucose oxidase (GOD), into the redox polymer films resulted in a two-to tenfold increase in the oxidation and reduction peak currents during cyclic voltammetry, while the glucose electrooxidation current was increased three-fold to ~1 mA/cm 2 for glucose sensors [21]. A redox polymer, poly(vinylimidazole), complexed with Os(4,4¢-dimethylbpy) 2 Cl has been electrodeposited on Ta-supported MWCNTs for glucose sensing [23]. In addition, a simple one-step electrodeposition method was developed for constructing an enzymechitosan (CHIT) -CNT composite by the electrolysis of H + at a direct-current power supply (3.0 V) to decrease the solubility of CHIT on electrode surface.…”

Biofunctionalization of Nanomaterials

“…For example, polytyrosine has been used as an electroactive label for the detection of prostate-specific antigen (PSA) with the limit of detection of about 1 nM [22]. A redox polymer, poly(vinylimidazole), complexed with Os(4,4¢-dimethylbpy) 2 Cl, has been electrodeposited on Ta-supported multiwalled carbon nanotubes (MWNTs) and enhanced the sensing sensitivity toward the glucose [23].…”

Enzyme-based Electrochemical Biosensors

“…This can be achieved by the surface functionalization of CNTs with ionic or hydrophilic groups or the functionalization of CNTs with water-soluable polymers. Based on this approach, MWCNTs are modified by redox polymer, poly(vinylimidazole) complexed with Os(4,4'dimethylbpy) 2 Cl(PVI-demeOs), resulting in the turning of MWCNT surface from hydrophobic to hydrophilic without changes of surface morporlogy (Cui et al, 2009). The prepared biosensor showed the enhanced sensing sensitivities induced by the redox polymer film, where the enzyme molecules was wired through the redox centers tethered on the mobile redox polymer backbones to the MWCNTs electrodes.…”