Versatile Chemical Approaches to Nanobiotechnology
Arun Chattopadhyay
Department of Chemistry and Centre for Nanotechnology
Indian Institute of Technology Guwahati
Guwahati 781 039, India
Email: arun@iitg.ernet.in
Abstract
Principles of chemistry not only offer a wide variety of routes to the generation of
nanocale materials but also provide ways and means of their efficient use. In our
laboratory, we try to utilize the versatility of chemical approaches in the generation of
nanoparticles (NPs) such as those of Au and Ag, their assembly and polymer composites,
and quantum dots (Qdots), with the aim of finding their potential applications in chemical
catalysis and chemical locomotion, lithography, their use as antimicrobial and anticancer
agents and in assays of biomolecules and pathogens.1-23 We primarily use metal NPs,
assembly of NPs and composites in order to fulfill the objectives.
For example, it is known that specific interactions between functionalized NPs and the
analyte give rise to important changes in the optical properties of the NPs, forming the
basis of sensing and assay. On the other hand, we have argued that interactions between
non-functionalized NPs such as Au NPs and molecules or biomolecules also carry
signature of specificity. The changes in the optical properties of the NPs as a
consequence could form a convenient and general basis for assays with superior
sensitivity. In this regard, a new method of easy and convenient assays for proteins with
high sensitivity has recently been developed. This is based on the broadening of UV-vis
extinction spectrum of Au NPs in the presence of proteins. Interestingly, the broadening
is not only dependent on the concentration of the protein but also on its conformation,
thus providing an assay with distinction of conformation.
We also work on the use of Ag or Au NPs and their composites for development of new
antimicrobial and anticancer agents and in estimation of bacteria. For example, we have
reported that a composite of Ag NP and chitosan works better as an antimicrobial agent
than either of the components at their concentrations in the composite. Additionally, in
the presence of iodine, which is known to get decomposed on the surface of Ag NPs, the
three-component system of Ag NP, chitosan and iodine works in tandem to provide the
highest level of activity. Our results indicated that the cationic polymer helped attract the
bacteria (due the overall negative charge of the cell surface) and Ag NPs induced pore
formation, while iodine increased reactive oxygen species generation in the bacteria. We
have also discovered that a new composite made of paracetamol dimer and Ag NP not
only killed bacteria but also linearized its DNA, providing a new mechanism of
antimicrobial activity. Additionally, we have demonstrated that the antimicrobial action
of Ag NPs primarily occur via perforation of cell walls of the bacteria.
We are also working on the development of combination therapy for anticancer
activity. For example, we have demonstrated that use of Ag NPs in conjunction with gene
therapy provides a viable alternative for anticancer treatment at low toxicity of the
constituents. Further, a nanocarrier for Ag NPs consisting of chitosan (and Ag NPs) has
been found to be efficient in inducing apoptosis in cancerous cells. Finally, we also work
on model chemical locomotives which have potentially important implications in
nanobiotechnology.
Acknowledgement. We thank the Department of Science and Technology, Department
of Biotechnology and Council of Scientific and Industrial Research, Government of India
for grants and fellowships.
References
1.
Plasmid DNA linearization in the antibacterial action of a new fluorescent Ag nanoparticle–paracetamol dimer composite.
Amaresh Kumar Sahoo, Md Palashuddin Sk, Siddhartha Sankar Ghosh and Arun Chattopadhyay. Nanoscale, (2011),
dx.doi.org/ DOI:10.1039/C1NR10389J.
2.
Enhanced Antibacterial Activity of Bimetallic Gold-Silver Core Shell Nanoparticle at low silver concentration. Madhuchanda
Banerjee, Shilpa Sharma, Arun Chattopadhyay and Siddhartha Sankar Ghosh. Nanoscale, (2011), dx.doi.org/
DOI:10.1039/C1NR10703H.
3.
Induction of apoptosis in cancer cells at low silver nanoparticle concentrations using chitosan nanocarrier. Pallab Sanpui, Arun
Chattopadhyay and Siddhartha Sankar Ghosh. ACS Applied Materials & Interfaces, (2011), 3(2), 218-228.
4.
In Situ Reversible Tuning of Photoluminescence of Mn2+-Doped ZnS Quantum Dots by Redox Chemistry. Raihana Begum and
Arun Chattopadhyay. Langmuir, (2011), 27 (10), 6433-6439.
5.
Estimating conformation content of a protein using citrate-stabilized Au nanoparticles. Jashmini Deka, Anumita Paul and Arun
Chattopadhyay, Nanoscale (2010) 2, 1405-1412.
6.
Incorporation of gene therapy vector in Chitosan stabilized Mn2+-doped ZnS Quantum. P. Sanpui P, S. B. Pandey, A.
Chattopadhyay and S.S. Ghosh. Material Letters, (2010), 64 (22), 2534-2537.
7.
Signaling gene cascade in silver nanoparticle induced apoptosis. P. Gopinath, Sonit Kumar Gogoi, Pallab Sanpui, Anumita Paul,
Arun Chattopadhyay and Siddhartha Sankar Ghosh. Colloids and Surfaces, B: Biointerfaces, (2010), 77(2), 240-245.
8.
Heightened Reactive Oxygen Species Generation in the Antimicrobial Activity of a Three Component Iodinated ChitosanSilver
Nanoparticle Composite, Madhuchanda Banerjee, Sadhucharan Mallick, Anumita Paul, Arun Chattopadhyay, and Siddhartha
Sankar Ghosh. Langmuir (2010) 26(8), 5901-5908.
9.
Sensitive Protein Assay with Distinction of Conformations Based on Visible Absorption Changes of Citrate-Stabilized Gold
Nanoparticles. Jashmini Deka, Anumita Paul and Arun Chattopadhyay. J. Phys. Chem. C ,(2009) 113 (17), pp 6936–6947.
10. Probing Au Nanoparticle Uptake by Enzyme Following the Digestion of a Starch-Au-Nanoparticle Composite. Jashmini Deka;
Anumita Paul, Aiyagari Ramesh and Arun Chattopadhyay, Langmuir, (2008), 24(18), 9945-9951.
11. Rapid Estimation of Bacteria by a Fluorescent Gold Nanoparticle-Polythiophene Composite. Biswa Ranjan Panda, Atul Kumar
Singh, Aiyagari Ramesh and Arun Chattopadhyay. Langmuir, (2008), 24(20), 11995-12000.
12. Green fluorescent protein for in situ synthesis of highly uniform Au nanoparticles and monitoring protein denaturation. Pallab
Sanpui, Shivendra B. Pandey, Siddhartha Sankar Ghosh and Arun Chattopadhyay. Journal of Colloid and Interface Science,
(2008), 326(1), 129-137.
13. The antibacterial properties of a novel chitosan-Ag-nanoparticle composite. Pallab Sanpui, A. Murugadoss, P. V. Durga Prasad,
Siddhartha Sankar Ghosh and Arun Chattopadhyay. International Journal of Food Microbiology, (2008), 124(2), 142-146.
14. Implications of silver nanoparticle induced cell apoptosis for in vitro gene therapy. P. Gopinath, Sonit Kumar Gogoi, Arun
Chattopadhyay and Siddhartha Sankar Ghosh. Nanotechnology (2008), 19(7), 075104/1-075104/10.
15. Retention of enzymatic activity of α-amylase in the reductive synthesis of gold nanoparticles. Abhijit Rangnekar, Tridib Kumar
Sarma, Atul Kumar Singh, Jashmini Deka, Aiyagari Ramesh and Arun Chattopadhyay. Langmuir, (2007), 23(10), 5700-5706.
16. Green fluorescent protein-expressing Escherichia coli as a model system for investigating the antimicrobial activities of silver
nanoparticles. Sonit Kumar Gogoi, P. Gopinath, Anumita Paul, A. Ramesh, Siddhartha Sankar Ghosh and Arun Chattopadhyay.
Langmuir (2006), 22(22), 9322-9328.
17. Plasmonic Signatures in the Composite Crystals of Gold Nanoparticles and p-Hydroxyacetanilide (Paracetamol). Subhojit Das,
Amaresh Kumar Sahoo, Siddhartha Sankar Ghosh and Arun Chattopadhyay. Langmuir, (2010), 26(20), 15714–15717.
18.
Stable Magnetic Chemical Locomotive with Pd Nanoparticle Incorporated Ferromagnetic Oxide. Krishna Kanti Dey, Kula
Kamal Senapati, Prodeep Phukan, Saurabh Basu, and Arun Chattopadhyay. J. Phys. Chem. C., (2011), 115 (26), pp 12708–
12715.
19.
Veering the motion of a magnetic chemical locomotive in a liquid. Krishna Kanti Dey, Deepika Sharma; Saurabh Basu and
Arun Chattopadhyay, J. Chem. Phys., (2008), 129(12), 121101/1-121101/4.
20.
Chemical Locomotives Based on Polymer Supported Catalytic Nanoparticles. Aditya Agrawal, Krishna Kanti Dey, Anumita
Paul, Saurabh Basu, and Arun Chattopadhyay, J. Phys. Chem. C, (2008), 112(8), 2797-2801.
21. Surface Area Controlled Differential Catalytic Activities of One-Dimensional Chain-like Arrays of Gold Nanoparticles. A.
Murugadoss and Arun Chattopadhyay, J. Phys. Chem. C, (2008), 112(30), 11265-11271.
22. Evaporation-induced patterns from droplets containing motile and nonmotile bacteria. Tittu Thomas Nellimoottil, Pinjala
Nagaraju Rao, Siddhartha Sankar Ghosh and Arun Chattopadhyay. Langmuir, (2007), 23(17), 8655-8658.
23. Au nanoparticles and polyaniline coated resin beads for simultaneous catalytic oxidation of glucose and colorimetric detection of
the product. Gitanjali Majumdar, Mausumi Goswami, Tridib Kumar Sarma, Anumita Paul and Arun Chattopadhyay. Langmuir,
(2005), 21(5), 1663-1667.
Dr. Arun Chattopadhyay is a Professor and Head of the Department of Chemistry at the
Indian Institute of Technology Guwahati. He obtained his M. Sc. in Chemistry from the
Indian Institute of Technology Kanpur (1988) and PhD in Chemical Physics from
Columbia University (New York) in the year 1992. He then went on to pursue
postdoctoral research work at Stanford University (1992-1995).
Dr. Chattopadhyay leads a group of research workers carrying out researches in the
frontier areas of nanoscale science and technology
Dr. Chattopadhyay has received several awards some of which are mentioned below.
(a) Materials Research Society of India Medal (2008).
(b) Swarnajayanti Fellowship of DST (2003-2004).
(c) Pegram Award (Columbia University, 1992).
(d) Best Undergraduate Student in Chemistry (M. Sc.) at IIT Kanpur (1988).