Molecular understanding of acetylcholinesterase adsorption on functionalized carbon nanotubes for enzymatic biosensors

The immobilization of acetylcholinesterase on different nanomaterials has been widely used in the field of amperometric organophosphorus pesticides (OPs) biosensors. However, the molecular adsorption mechanism of acetylcholinesterase on the nanomaterials...

Enhanced electrical conductivity of anticorrosive coatings by functionalized carbon nanotubes: effect of hydrogen bonding

Carbon nanotubes (CNTs) and nanofibers (CNFs) are well-known nano additives that produce coating materials with high electrical and thermal conductivity and corrosion resistance. In this paper, coating materials incorporating hydrogen bonding offered significantly lower electrical resistance. The hydrogen bonding formed between functionalized carbon nanotubes and ethanol helped create a well-dispersed carbon nanotube network as the electron pathways. Electrical resistivity as low as 6.8 Ω⋅cm has been achieved by adding 4.5 wt.% functionalized multiwalled carbon nanotubes (MWNT-OH) to 75%Polyurethane/25%Ethanol. Moreover, the thermal conductivity of Polyurethane was improved by 332% with 10 wt.% addition of CNF. Electrochemical methods were used to evaluate the anti-corrosion properties of the fabricated coating materials. Polyurethane with the addition of 3 wt.% of MWNT-OH showed an excellent corrosion rate of 5.105×10-3 mm/year, with a protection efficiency of 99.5% against corrosive environments. The adhesion properties of the coating materials were measured following ASTM standard test methods. Polyurethane with 3 wt.% of MWNT-OH belonged to class 5 (ASTM D3359), indicating the outstanding adhesion of the coating to the substrate. These nano coatings with enhanced electrical, thermal, and anti-corrosion properties consist of a choice of traditional coating materials, such as Polyurethane, yielding coating durability with the ability to tailor the electrical and thermal properties to fit the desired application.

Molecular dynamics simulation study of doxorubicin adsorption on functionalized carbon nanotubes with folic acid and tryptophan

In this work, molecular dynamics (MD) simulation is used to study the adsorption of the anticancer drug, doxorubicin (DOX), on the wall or surface of pristine and functionalized carbon nanotubes (FCNTs) in an aqueous solution. Initially, the CNTs were functionalized by tryptophan (Trp) and folic acid (FA), and then the DOX molecules were added to the system. The simulation results showed that the drug molecules can intensely interact with the FCNTs at physiological pH. Furthermore, it was found that as a result of functionalization, the solubility of FCNTs in an aqueous solution increases significantly. The effect of pH variation on drug release from both pristine and FCNTs was also investigated. The obtained results indicated that in acidic environments due to protonation of functional groups (Trp) and as a result of repulsive interaction between the DOX molecule and functional groups, the release of DOX molecules from FCNT’s surface is facilitated. The drug release is also strongly dependent on the pH and protonated state of DOX and FCNT.