Molecular discriminators using single wall carbon nanotubes

Real-time electro-diffusion method to discriminate carbon nanomaterials

We report both the experimental and theoretical insights of differential electro-diffusion behavior of carbon nanomaterials (e.g. single wall, multiwall carbon nanotubes, and graphene). We thus discriminate one from the other in a soft gel system. The differential mobility of such material depends on their intrinsic properties, both extend and rate of migration bearing the discriminatory signature. The mobility analysis is made by a real time monitoring of the respective bands.

Enhanced functionality and stabilization of a cold active laccase using nanotechnology based activation-immobilization

A simple nanotechnology based immobilization technique for imparting psychrostability and enhanced activity to a psychrophilic laccase has been described here. Laccase from a psychrophile was supplemented with Copper oxide nanoparticles (NP) corresponding to copper (NP-laccase), the cationic activator of this enzyme and entrapped in single walled nanotube (SWNT). The activity and stability of laccase was enhanced both at temperatures as low as 4°C and as high as 80°C in presence of NP and SWNT. The enzyme could be released and re-trapped (in SWNT) multiple times while retaining significant activity. Laccase, immobilized in SWNT, retained its activity after repeated freezing and thawing. This unique capability of SWNT to activate and stabilize cold active enzymes at temperatures much lower or higher than their optimal range may be utilized for processes that require bio-conversion at low temperatures while allowing for shifts to higher temperature if so required.

Reusable glucose sensing using carbon nanotube-based self-assembly

Lipid functionalized single walled carbon nanotube-based self assembly forms a super-micellar structure. This assemblage has been exploited to trap glucose oxidase in a molecular cargo for glucose sensing. The advantage of such a molecular trap is that all components of this unique structure (both the trapping shell and the entrapped enzyme) are reusable and rechargeable. The unique feature of this sensing method lies in the solid state functionalization of single walled carbon nanotubes that facilitates liquid state immobilization of the enzyme. The method can be used for soft-immobilization (a new paradigm in enzyme immobilization) of enzymes with better thermostability that is imparted by the strong hydrophobic environment provided through encapsulation by the nanotubes.