Chemistry

Research Areas

Anti-cancer Drugs
Cancer is caused when cells divide uncontrollably and start to spread into surrounding tissues. Quinazoline, pyrazolopyrimidine, and pyrimidinyl-thiazoles are three important pharmacophores that are most widely seen in small molecular anti-cancer drugs used as kinase inhibitors. In the current study, novel molecules containing these active fragments are synthesized and studied to understand their inhibitory activities against various cancer types. Molecules with promising anti-cancer activities will be further evaluated for their selectivity in inhibition of certain cancer types, and the mechanism of inhibition involved.

Atmospheric Chemistry
Air pollution studies related to aerosols and volatile organic compounds (VOCs) and persistent organic pollutants (POP) are being carried out in various metropolitan cities in India. Studies related to the determination of reactive oxidation species present in particulate matter (PM10 and PM2.5) are carried out using yeast and cellular studies. Development of carbon-based adsorbents for preconcentration of highly reactive volatile organic compounds. Development of analytical techniques for the screening and the quantification of microplastics, organic and inorganic compounds in complex environmental matrices based on LC-MS-QQQ, LC-MS-QTof, and MP-AES are also being carried out.

Synthesis of novel pH-independent, eco-friendly and economically viable PVA based adsorbents for water treatment
The research work involves synthesis of novel mesoporous PVA-metal hydrogel beads by mixing metal ions, in concentration range 0.01-0.3 mol L-1 with 10 wt% PVA solution and glutaraldehyde. The right combination of metal ions is necessary for synthesis of hydrogel beads to ensure faster kinetics for adsorption of fluoride. These novel mesoporous metal ion-PVA based hydrogel beads will also be used for simultaneous removal of arsenate, chromate and fluoride.
A novel hybrid hydrogel network of graphene oxide-polyethylenimine-polyvinyl alcohol (GPPH) beads via the microwave route will be synthesized which could be used for effective removal of both cationic and anionic contaminants.
Surface modification with hydrophobic/hydrophilic groups in a novel hybrid hydrogel network of graphene oxide-polyethylenimine-polyvinyl alcohol hydrogel beads could be used for oil-water separation and removal of other harmful organic contaminants.

Synthesis of Small Molecules with Potent Biological Activity
Andrographis paniculata is an Ayurvedic herb known for its medicinal activities. Andrographolide, the main constituent of Andrographis paniculata and its analogues, possesses anti-cancer, anti-inflammatory, anti-bacterial, anti-diabetic, anti-HIV, FXR antagonist, and hepato-protective properties. In this regard, we have synthesized several derivatives of andrographolide, isoandrographolide and 12-hydroxy andrographolide and extensively studied for their anti-cancer properties. Pyrazole-andrographolide derivatives have been synthesized and their anticancer activity has been carried out. The mechanism of anticancer activity of these novel compounds has also been investigated. These compounds have also been investigated for their activity against SARS-COVID-19 by in silico studies. Arjunolic acid, an active component from Terminilia arjuna, is known to possess cardioprotective properties against myocardial necrosis. A novel method of isolation of arjunolic and asiatic acid has been developed. Various derivatives of arjunolic acid have been synthesized and their anti-cancer properties have been explored.

Rational Design of Thermally Activated Delayed Fluorescence (TADF) Molecules for OLED Applications – A Computational and Spectroscopic Approach
A typical Organic Light Emitting Diode (OLED) structure consists of a thin layer of organic electroluminescent material sandwiched between two electrodes mounted on transparent flexible or rigid substrates such as glass, plastic etc. They work on the principle of electroluminescence wherein light emission occurs on the application of voltage and find applications in displays. TADF based OLED emitters are a relatively new class of emitter materials that promise efficient and long-lifetime performance without any heavy metals. They produce light by harvesting both singlet and triplet excitons and are emerging as next-generation organic electroluminescent materials. For a molecule to act as a TADF emitter it must have a small singlet-triplet energy gap which ensures high reverse intersystem (RISC) crossing which inturn helps to increase the photoluminescence quantum efficiency and consequentially electroluminescence quantum efficiency. Designing molecules involving donor, acceptor molecules with and without linker is the aim of this project. The project involves both computational calculations and experimental benchwork. The computational work will involve designing various novel donor-acceptor organic molecules interspersed with or without a linker and screening them for good TADF properties and short-listing the best ones for experimental work. The experimental work will involve performing steady-state absorption and fluorescence measurements and ultrafast spectroscopic measurements at picosecond (10-12 s) and femtosecond (10-15 s) timescales, electrochemistry experiments etc on the short-listed molecules.

Designing Non-toxic Polymer Nanocomposites for Next-Generation Biomedical Devices Through Computational Modelling
Polyvinyl chloride (PVC) is one of the widely used polymers in biomedical devices and in the health industry in general. It has favourable properties for use in various applications such as mechanical, optical, etc. It is rigid and thus necessitates the use of a plasticizer to obtain the desired flexibility which is important in many applications. Plasticizer not only ensures sufficient flexibility to the polymer but also alters the glass transition temperature which is important for many applications. DEHP (di(2-ethylhexyl) phthalate) happens to be one of the most widely used plasticizers. Though DEHP supersedes many plasticizers it was recently found to have toxicity issues. Designing new plasticizer molecules to overcome the harmful effects of these plasticizers through computational modelling is one objective of this project.
Further, ceria’s (CeO2) high oxygen storage capacity and high oxygen mobility in the lattice encouraged a broad application of ceria to biological effects related to redox reactions. It was also seen that CeO2 has anti-inflammatory, anti-cancer and angiogenesis effects. Also, from the literature, it is known that ceria nanoparticles are known to increase the shelf life of stored blood due to reduced oxidative hemolysis. Designing novel polymer nanocomposites using PVC and CeO2 with and without the incorporation of a plasticizer through systematic structure-property studies is the second objective of this project.

Novel plasmonic sensing platforms for clinical diagnostics and environment monitoring applications
Low-dimensional polymeric nanoscale materials such as 2D thin film materials and 1D nanostructures have gained attention in the areas of composite structures, electronics, biosensors, and plasmonics. Of these, 1D polymeric nanofibers have been utilized for various applications over two decades and are seen as potential replacements for thin films due to their excellent physical and mechanical properties. Among the several methods to fabricate 1D nanostructures, electrospinning is a well-established, versatile, and cost-effective technique for the production of nanofibers at submicron levels. The synthesis of electrospun polymer nanofibers doped with different nanomaterials were developed and utilized in plasmon-coupled fluorescence studies to obtain augmented enhancements. The nanofibers present emission enhancements that are greater and highly polarized even at increased concentrations of polymer vis-à-vis thin films that show dual polarizations at higher concentrations of polymer showing that 1D nanofibers can be used as green & and low-cost replacements for 2D nano-thin films.

Bio-polymers as effective adsorbents for greenhouse gas removal
Bio-polymers have taken a center stage, in recent years, in various scientific disciplines because of their outstanding properties and multiple applications. The major advantage is also due to their abundance, low cost and environment-friendly nature. Suitable modifications on these naturally available molecules could serve as the basis for numerous novel materials with enhanced properties. In the current study, biopolymers were investigated as suitable adsorbents for CO gas adsorption. The polar groups on the monomeric units can bind the CO molecules via non-bonded interactions. Since biopolymers are bulk molecules and adsorption being a surface phenomenon, quantum mechanical studies on their constituent monomers play an important role in identifying nature and strength of interactions occurring between adsorbate and adsorbent at the molecular level.

Tuning the optical properties of fluorescent nanomaterials to obtain NIR emission for anti-counterfeiting and multi-colour imaging
Well-ordered patterns of nanomaterials as biosensors have achieved a lot of interest for the detection of analytes because of its enhanced selectivity and sensitivity towards specific analytes. Well-ordered assembly of zero-dimensional quantum dots on polymer-based porous film for trace-level detection of toxic metal ions, toxic food adulterants, and banned chemical substances in foodstuffs can be fabricated using a low-cost soft template method known as the Breath Figure method. This novel fabrication method is expected to work directly on analytes like environmental pollutants and food toxins with high sensitivity and selectivity.

Fabrication of well-ordered assembly of zero-dimensional quantum dots for environmental monitoring and food safety applications
Well-ordered patterns of nanomaterials as biosensors have achieved a lot of interest for the detection of analytes because of its enhanced selectivity and sensitivity towards specific analytes. Well-ordered assembly of zero-dimensional quantum dots on polymer-based porous film for trace-level detection of toxic metal ions, toxic food adulterants, and banned chemical substances in foodstuffs can be fabricated using a low-cost soft template method known as the Breath Figure method. This novel fabrication method is expected to work directly on analytes like environmental pollutants and food toxins with high sensitivity and selectivity.

Waste derived multifunctional fluorescent carbon nanodots as potential antimicrobial, antioxidant and anticancer agent
Food waste-derived fluorescent carbon nanodots as potential antioxidants, antimicrobial, and anticancer agents represents a groundbreaking approach to both waste management and healthcare. By repurposing the food wastes such as fruit peels, vegetable scraps, and other organic residues into fluorescent carbon nanodots we are not only addressing the issue of waste disposal but also tapping into a source of valuable materials with promising biomedical applications. These carbon nanodots exhibit intrinsic fluorescence that can be harnessed for imaging and sensing applications, while their inherent antioxidant properties offer potential for combating oxidative stress. Additionally, their antimicrobial and anticancer activities are being explored to develop new therapeutic agents and treatment modalities. This innovative approach not only enhances the sustainability of nanomaterial production but also opens avenues for the development of multifunctional agents in medical and environmental applications.