• SOHEILA KASHANIAN

Articles written in Bulletin of Materials Science

• Laccase immobilized onto graphene oxide nanosheets and electrodeposited gold–cetyltrimethylammonium bromide complex to fabricate a novel catechol biosensor

In this study, a new biosensor is developed with reliable and easy-to-use biodevice properties for catechol determination in real samples. A method is proposed for the fabrication of biosensors to sense catechol based on theadsorption method of laccase immobilization. Hence, a glassy carbon electrode was modified via graphene oxide nanosheets and then it was modified with a gold–cetyltrimethylammonium bromide nanocomposite to adsorb and immobilize laccase on the electrode surface. The results showed laccase immobilization onto the reformed glassy carbon electrode, and a direct electron transfer reaction between laccase and the electrode. The mechanism of electron transferring was EC$^{\prime}$. Also, $k_s$ and $\alpha$ were calculated as 0.41 s$^{−1}$ and 0.33, respectively. For this biosensor two linear ranges, $0.1 \times 10^{−6}$ to $5 \times 10^{−6}$ M and $16.7\times 10^{−6}$ to $166 \times 10^{−6}$ M, and a detection limit of $1.5 \times 10^{−6}$ M were obtained.

• Novel fabrication of a laccase biosensor to detect phenolic compounds using a carboxylated multiwalled carbon nanotube on the electropolymerized support

Biosensors research is one of the fastest growing fields in which tens of thousands of papers have been published over the years; even more, numerous biosensors have been developed for the detection of phenolic compounds, such as catechol which reacts with an appropriate enzymatic bioreceptor like laccase. A biosensing electrode for catechol detection was investigated by covalent immobilization of laccase on a glassy carbon electrode modified by conducting polymers built of poly(3,4-ethylenedioxythiophene), gold nanoparticles and carboxylated multiwalled carbon nanotubes. The fabrication process of the sensing surface was investigated by Fourier transform infrared spectroscopy, scanning electron microscopy and electrochemical procedures. The electrochemical results demonstrate that the enzyme was immobilized covalently onto the modified glassy carbon electrode by the interaction between carboxyl groups of the carboxylated multiwalled carbon nanotubes and laccase. The biosensor demonstrates a direct electron transfer between the electrode and immobilized laccase. Under optimum conditions, it presented two linear responses in the range of 0.1–0.5 and 11.99–94.11 $\mu$M. The limits ofdetection were found to be 0.11 and 12.26 $\mu$M.

• Stealth cross-linked polymeric nanoparticles for passive drug targeting: a combination of molecular docking and comprehensive in vitro assay

Till date, several studies have reported magnetic drug targeting as well as passive drug delivery. In this study, the passive characteristic of PEGylated carriers with a neutral surface charge rather than chitosan (CS)-based nanoparticles (NPs) with a positive charge was proved using molecular docking. The complete and without flaw stealth CS-coated magnetic NPs (mNPs) loaded with an anticancer drug for intravenous drug delivery were prepared using a modified ionic crosslinking method. The physicochemical properties of the prepared magnetic-CS NPs were characterized in detail. The transmission electron micrographs of NPs showed an uniform particle morphology with an average diameter of smaller than 10 nm. The average IC50 values of the drug in PEGylated NPs for MCF-7 and PC-12 cells were 44 and 72 lM, respectively. The fabricated stealth NPs can increase the cytotoxicity and cell permeability of formulation that may release the entire drug in targeted shape to objective tissues that were firstly proved by molecular docking. This strategy showed a reduction in up taking of mNPs by the reticuloendothelial system, which indeed increases the concentration of therapeutic agent(s) in the target site.

• # Bulletin of Materials Science

Volume 44, 2021
All articles
Continuous Article Publishing mode

• # Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020