Carbon Nanotubes: A Review on Structure and Their Interaction with Proteins
Table 6
Noncovalent immobilization of protein and enzymes by indirect specific adsorption.
Protein or Enzyme immobilized
Types of interaction
References
Glucose oxidase
(i) Surface of CNTs was positively charged by coating poly (sodium 4-styrenesulfonate) combined with ionic liquids. (ii) The enzyme was adsorbed onto nanotube composites through electrostatic interactions.
(i) single stranded DNA was wrapped on CNTs, and enzymes were immobilized onto DNA-wrapped CNTs. (ii) The binding of DNA onto CNTs appears to be primarily due to π -π stacking interaction, with the plane of the aromatic-nucleotide bases oriented parallel to the surface of the nanotube.
(i) Streptavidin and flavin adenine dinucleotide have also been used as the linking molecules between enzymes and CNTs. (ii) DNAzyme immobilized onto CNTs attached with streptavidin via stable amide linkages. (iii) Glucose oxidase has been immobilized onto CNTs functionalized with the flavin adenine dinucleotide via amide linkages.
(i) Enzymes were adsorbed onto CNTs which were coated with surfactants such as Triton X-100, sodium dodecyl sulfate, and cetyltrimethylammonium bromide. (ii) Enzymes and surfactants are coassembled onto the CNTs. The CNTs are sonicated in the solution of a surfactant. When enzyme is mixed with the suspension, it binds to the CNTs more strongly than the surfactant and displaces the surfactant to gain access to the CNT surface.
