Microwave mediated synthesis of dopamine functionalized copper sulphide nanoparticles: An effective catalyst for visible light driven degradation of methlyene blue dye.

The current work highlights the potential aptitude of copper sulphide (CuS) nanoparticles as cost and energy-effective photo-catalyst for degrading methlyene blue dye under visible light. The surface modified CuS nanoparticles with dopamine (DOP) were prepared by using fast and cost effective microwave assisted methodology. Here, DOP act as biological ligand for the reduction and capping of CuS nanoparticles. The structural and morphological analyses revealed the size controlled synthesis of CuS in presence of DOP with higher thermal stability. The bio-compatibility and non-toxic behaviour of CuS@DOP nanoparticles was evaluated against L929 cell lines and on E. coli and S. aureus strains. The visible light driven photocatalytic activity of the synthesized CuS@DOP was scrutinized for the degradation of methylene blue (MB) dyes, as a model of water contaminants. The photocatalytic degradation of MB by CuS@DOP attained 97% after 10 min of visible light irradiation. The effect of catalyst dose, pH, initial concentration of MB dye, electrolytes, contact time, synergic effect of photolysis and catalysis were studied in detail for optimizing the degradation efficiency of CuS@DOP. The mechanism of CuS@DOP photocatalysis and the formed degraded products were analyzed by using LC/MS technique. The reusability and stability of photocatalyst was confirmed by reusing the catalyst for six successive runs with catalytic performance as high as 80%. Thus, CuS@DOP NPs acted as cost effective, non-toxic visible light driven photo-catalyst for the degradation of organic dye from waste water.

Dopamine functionalized CuO nanoparticles: A high valued "turn on" colorimetric biosensor for detecting cysteine in human serum and urine samples.

An attempt has been made to design one step synthesis of dopamine coated copper oxide nanoparticles (CuO@DOP NPs) by using microwave radiation method. The luminescent properties of CuO@DOP NPs have been explored for making colorimetric and visual biosensor for L-cys. Natural occurring dopamine has used as a precursor for the coating of CuO NPs that provides stability and generates functionality for the sensing of L-Cysteine (L-Cys). Being one of the important amino acid, L-cys has shown a fundamental role in living species due to the existence of sulfhydryl bonding which further affect the process of protein synthesis in living system. Therefore sensing of L-cys by using CuO@DOP NPs deserves higher consideration. Further, morphological and size parameters have been analyzed by using FESEM and HRTEM techniques. Surface interaction and coating of dopamine over CuO NPs has been examined through FTIR and TGA analysis. The non-toxicity and bio-compatibility of CuO@DOP NPs has been evaluated against L929 cell lines and on bacterial species. A computational study using DFT has been performed to check the possible mechanism of interaction between the CuO@DOP NPs and L-Cys. The higher value of detection limit (35 nM) has further shown its potential scope in sensing L-cys. The interference studies in presence of other amino acids have also taken into consideration for checking the selectivity and sensitivity of designed sensor. The applicability of prepared sensor has further been tested for real human blood serum and urine samples for detecting the presence of L-Cys. The as developed sensor of CuO@DOP NPs has provided rapid and selective sensing ability towards L-Cys over a wide range of concentration and bio-compatibility towards living entity. NOVELTY STATEMENT: Herein, the application of unique chemical and photo-luminescent properties of CuO NPs have been chosen for the fabrication of new type of fluorophore to complement conventional types of biosensor for L-Cys. The synthesis of CuO based biosensor has been achieved via an economically viable microwave assisted method. The article has not been published in any language anywhere and that it is not under simultaneous consideration by another journal. The current work is novel.

Nanosorbent of hydroxyapatite for atrazine: A new approach for combating agricultural runoffs.

The attention of current work was on the fabrication of effective nanoadsorbent of hydroxyapatite (HAp) for the controlled release of atrazine (ATZ) formulation. The ATZ-HAp complex (ATZ@HAp) was able to inhibit the growth of Brassica sp. under in situ conditions. This developed methodology aspires to cease the agricultural runoffs of ATZ applied with the HAp adjuvant and ensure their effective functioning. The efficacy of the protocol was mainly accomplished by adsorbing ATZ over the surface of HAp NPs that restricted its premature runoff and promoted the prolonged herbicidal efficiency. The influence of fundamental parameters i.e., HAp dose, ATZ dose and initial pH on the adsorption process was investigated systematically. The suitability of ATZ@HAp complex for real world application was adjudged after proofing its toxicological behaviour and its role in Zea mays plantations. The complex was found to be non-toxic and nurturing due to its phosphate rich nature. Further investigations of ATZ@HAp complex and its effect on the non-target species will help in establishing an effective framework for their commercial use in agricultural practices.