• Resolution Point : 0.19 nm, Line : 0.1nm
• Magnification : 50 x - 1.5M x
• Accelerating voltage : 120 kV and 200 kV.
• Emitter : Field Emission Gun (ZrO/W)
• Electron gun lens : Electrostatic lens.
• Vacuum pumps for rough evacuation: Rotary pump/oil diffusion pump
• Molecular pump for fine evacuation: Sputter-ion pump (pressure: 10^-8 Pa)

• FEG featuring a high brightness and a high stability realizes structural imaging at atomic resolution.
• Highly bright sub-nanometre sized probe enables us to perform an ultimately sensitive analysis of a sample at sub-nanometre resolution.
• With FEG, the contrast of high-resolution image is also improved because it provides a highly coherent illumination with a narrow energy spread.
• With optionally available piezo specimen drive system, specimen can be shifted at sub-nanometre resolution with a range of ± 1.2 μm.
• The design concept enables us to integrate various analytical instruments and/or cameras such as EDS and CCD cameras.
• This feature is essential for ultrahigh resolution in scanning transmission microscopy and in an analysis of a Nano-scaled sample.

Innovative scientific technologies used in today's nanotechnology are making remarkable progress. In research on novel materials such as carbon nanotubes, semiconductors and ceramics, as nanometre-scale evaluation and analysis are essential. This electron microscope is equipped with a field emission electron gun (FEG) that produces high brightness (100 times greater than LaB6) and is highly stable. This feature is essential for Nano-scale ultrahigh resolution analysis. HRTEM has an imaging mode that allows the imaging of the crystallographic structure of a sample at an atomic scale. Because of its high resolution, it is an invaluable tool to study Nano scale properties of crystalline material such as semiconductors, ceramics, metals, etc. The microscope resolution is 1.9 angstrom. HRTEM is the tool useful in imaging (semiconductor, core-shell nanoparticles, grain boundaries, etc.), to see structure details of nanotubes, nanowires, nanoparticles and so on.

• What is an electron microscope (EM)?
  The electron microscope (EM) uses a beam of electrons to form an image of a specimen. An EM is capable of much higher magnifications and has a greater resolving power than an optical microscope, allowing it to visualize much smaller objects in finer detail.
  
  There are two basic types of electron microscopes: the transmission electron microscope (TEM) produces high resolution two dimensional images, while a scanning electron microscope (SEM) scans surfaces of specimens to produce three-dimensional images.
  
  EMs operates under vacuum conditions and are generally large pieces of equipment. They mostly stand alone in a small, specially-designed room and require trained personnel to operate them.
• What is transmission electron microscopy (TEM)?
  Transmission electron microscopy (TEM) is a technique whereby a beam of electrons is partially transmitted through an ultra thin specimen, interacting with the specimen as it passes through.
  
  An image is formed from the interaction of the electrons transmitted through the specimen. This image is magnified and focused onto an imaging device, such as a fluorescent screen, a layer of photographic film or, increasingly, it is detected by a sensor such as a CCD camera.
  
  TEMs are capable of imaging at a significantly higher resolution than light microscopes, owing to the small wavelength of electrons, in comparison to light. This enables the examination of fine specimen detail - even as small as a single column of atoms, which is tens of thousands times smaller than the smallest resolvable object in a light microscope. The highest resolution achieved on an aberration-corrected TEM is in the region of 0.5 Angstroms.
  
  The TEM is a major analytical tool in a wide range of scientific fields, in both physical and biological sciences.
• What information does the TEM provide? Why would I use it?
  • The transmission electron microscope (TEM) is used to examine the structure, composition, and properties of specimens in nanoscale detail. It can be used for image morphology of samples, e.g. view sections of material, fine powders suspended on a thin film, etc.
  • TEM cannot take colour images. Colour is sometimes added artificially to TEM images.
  • TEM cannot image through thick samples: the usual sample thickness is less than 100nm. Electrons cannot readily penetrate sections much thicker than 200nm.
• What is electron microscopy (EM) specimen preparation?
  In most cases, materials to be viewed under a transmission electron microscope (TEM) or scanning electron microscope (SEM) require processing to produce a suitable specimen. The technique, or techniques, required varies depending on the specimen and the analysis required.
• What is transmission electron microscopy (HRTEM) specimen preparation?
  A vast range of processing methods and technologies are available for both materials and biological specimens. These processes and associated instrumentation include chemical fixation, embedding and ultra-thin sectioning of biological material, and the thinning of metal specimens prior to TEM examination. The resultant specimens are typically held during observation on TEM support grids.
• Why sample preparation is required?
  • To increase contrast: heavy atoms interact stronger with electrons than bio molecules (C, N, O, S, P)
  • Positive Staining:
  • treat sample with solution of salt like uranyl acetate, lead citrate, osmium tetraoxide – object is black on light background
  • Negative Staining:
    Place sample on dried film of heavy metal salt – object is light spot on black background.

Publication Details:

Patent/patent applications:*

1. Rohit Srivastava and co-workers Dual therapeutic disintegrable GNR-Liposome nanohybrid for Plasmon is photo thermal Cancer theranostic: IDF: 10-04-17:

2. Rohit Srivastava and co-workers Red emissive photo triggered Plasmonic nano-rods for deep tissue visualisation and localized tumour ablation: IDF: 03- 11-17

3. Rohit Srivastava and co-workers Biodegradable fluorescent liposomal Nano composites and method of preparation thereof: IDF: 03-11-2017: provisional

4. Rohit Srivastava and co-workers Multistimuli bioresponsive fluorescent annotated hollow mesoporous silica for cancer Theranostics : IDF: 03-11-2017:

5. Rohit Srivastava and co-workers Room temperature synthesis of biocompatible porous silica nanoparticles using lipid as a structure directing agent: IDF: 04- 12-2017

6. Rohit Srivastava and co-workers Rapid and scalable microwave assisted hydrothermal method for synthesis of fluorescent carbon spheres: IDF: 07-02- 2018:

7. Rohit Srivastava and co-workers Polycaprolactone based Plasmon is nanoshells and applications thereof: IDF: 17-02-2018:

8. Rohit Srivastava and co-workers Red emissive liposomal nanopitchers for localised diagnosis and phototriggered tumour ablation: IDF: 13-03-2018:

9. Rohit Srivastava and co-workers One step biocompatible frolic acid stabilised end-end assembled gold nanorods and usage thereof: IDF: 21-03-18:

10. Rohit Srivastava and co-workers Rapid and scalable bioresponsive plasmonic gated functional nanohybrid and their use of, US Patent, 20-16-18:

11. Rohit Srivastava and co-workers One-step scalable design of biocompatible gold nanorods for nanomedicine, US Patent, 20-16-18:

12. Kumawat, Mukesh Kumar; Thakur, Mukeshchand; Gurung, Raju B; Srivastava, Rohit; Process for the synthesis of multi-fluorescent carbon nanostructures. Indian Patent Application (IPA no. 201621011794)

13. Kumawat, Mukesh Kumar; Thakur, Mukeshchand; Gurung, Raju B; Srivastava, Rohit; Red luminescent graphene quantum dots, synthesis and applications thereof. Indian Patent Application (IPA No. 201721016198)

14. Chauhan, Deepak Singh; Kumawat, Mukesh Kumar; Srivastava, Rohit. Near infra-red hybrid nanomaterials and graphene oxide for theranostic applications. Indian Patent Application (IPA no. 4747/MUM/2015)

15. Lakkakula, J. R.; Tharayil, Deepika Divakaran; Thakur, Mukeshchand; Kumawat, Mukesh Kumar; Srivastava, Rohit. Cyclodextrin functionalized inorganic nanostructures: synthesis and applications thereof. Indian Patent Application (IPA No. 201721016954) (Provisional).

16. Bahadur, Rohan; Thakur, Mukeshchand; Kumawat, Mukesh Kumar; Srivastava, Rohit. Method for preparing graphene quantum dots (GQDs) and uses thereof. Indian Patent Application (IPA No. 201721038918) (Provisional)

*Publications:*

1. Fluorescence Stability Study of MPA-CdTe Quantum Dots in Various Biochemical Buffers. Vivek Borse, A Kashikar, R Srivastava Journal of Nanoscience and Nanotechnology 18, 2582–2591, 2018

2. N-doped multi-fluorescent carbon dots for ‘turn off-on’ silver-biothiol dual sensing and mammalian cell imaging application. Vivek Borse, M Thakur, S Sengupta, R Srivastava. Sensors and Actuators B: Chemical 248, 481-192, 2017

3. CdTe quantum dots: aqueous phase synthesis, stability studies and protein conjugation for development of biosensors. Vivek Borse, M Sadawana, R Srivastava. Nanophotonics VI, SPIE Photonics Europe 2016 9884 (988423), 2016

4. ‘Turn-on’ fluorescence assay for inorganic phosphate sensing Vivek Borse, P Jain, M Sadawana, R Srivastava. Sensors and Actuators B: Chemical 225, 340–347, 2015

5. Rohit Srivastava and co-workers, Disintegrable NIR light triggered gold nanorods supported liposomal nanohybrids for cancer theranostics, Bioconjugate Chem., 2018, 29, 1510-1518

6. Rohit Srivastava and co-workers, NIR light-triggered shrinkable thermoresponsive PNVCL nanoshells for cancer theranostics, RSC.ADV., 2017, 7, 44026-44034.

7. Rohit Srivastava and co-workers, Facile synthesis of plasmonic zein nanoshells for imaging-guided photothermal cancer therapy, Mater. Sci. Engg. C, 2018, 90, 539-548.

8. Rohit Srivastava and co-workers, Plasmonic Carbon Nanohybrids for Repetitive and Highly Localized Photothermal Cancer Therapy, Colloids Surf B Biointerfaces, 2018.

9. Rohit Srivastava and co-workers, Biodegradable fluorescent nanohybrid for photo-driven tumor diagnosis and tumor growth inhibition, Nanoscale. (Revision submitted)

10. Mukesh Kumar Kumawat, Mukeshchand Thakur, Raju B Gurung, Rohit Srivastava. Graphene Quantum Dots from Mangifera indica: Application in Near-Infrared Bioimaging and Intracellular Nanothermometry. ACS Sustainable Chemistry & Engineering 5 (2), 1382-1391

11. M Thakur, MK Kumawat, R Srivastava. Multifunctional graphene quantum dots for combined photothermal and photodynamic therapy coupled with cancer cell tracking applications. RSC Advances 7 (9), 5251-5261.

12. MK Kumawat, M Thakur, RB Gurung, R Srivastava. Graphene quantum dots for cell proliferation, nucleus imaging, and photoluminescent sensing applications. Scientific reports 7 (1), 15858.

13. MK Kumawat, M Thakur, JR Lakkakula, D Divakaran, R Srivastava. Evolution of thiol-capped gold nanoclusters into larger gold nanoparticles under electron beam irradiation. Micron 95, 1-6.

14. Subhadeep Das, Mukesh K Kumawat, Srivastav Ranganathan, Rakesh Kumar, Jozef Adamcik, Pradeep Kadu, Ranjith Padinhateeri, Rohit Srivastava, Raffaele. Mezzenga, Samir. Maji. Cell Alignment on Graphene–Amyloid Composites. Advanced Materials Interfaces 1800621.

15. JR Lakkakula, D Divakaran, M Thakur, MK Kumawat, R Srivastava. Cyclodextrin-stabilized Gold nanoclusters for bioimaging and selective labelfree intracellular sensing of Co2+ ions. Sensors and Actuators B: Chemical 262, 270-281.

16. Krista R Khiangte,JS Rathore, S Das, RS Pokharia, J Schmidt, H J Osten, S. Mahapatra et al J Appl Phys 124,065704(2018).

17. Krista R Khiangte,J S Rathore, J Schmidt, H J Osten, A LahaS. Mahapatra et al Applied Phys 51, 32(2018)

18. “Recovery of Active Surface Sites of Shape-Controlled Platinum Nanoparticles Contaminated with Halide Ions and Its Effect on Surface-Structure”, Ruttala Devivaraprasad, Tathagata Kar, Pradipkumar Leuaa, and Manoj Neergat, Journal of The Electrochemical Society, 164 (2017), H551 H560. ‒

2021: 

1. Jinal M. Mehta, Nishant K. Jain, Deepak S. Chauhan, Rajendra Prasad, Mukesh K. Kumawat, Mukesh Dhanka, Asifkhan Shanavas, Rohit Srivastava, Emissive radiodense stealth plasmonic nanohybrid as X-ray contrast and photo-ablative agent of cancer cells, Materials Today Communications, Volume 27, 2021,https://doi.org/10.1016/ j.mtcomm.2021.102181

2. Barkha Singh, Rohan Bahadur, Misah Rangara, Mayuri N. Gandhi, and Rohit Srivastava*, Influence of Surface States on the Optical and Cellular Property of Thermally Stable Red Emissive Graphitic Carbon Dots, ACS Appl. Bio Mater.
2021, 4, 5, 4641–4651

3. Anivind Kaur Bindra, Sivaramapanicker Sreejith, Rajendra Prasad, Mahadeo Gorain, Rijil Thomas, Deblin Jana, Mui HoonNai, Dongdong Wang, Abhimanyu https://ams.iitb.ac.in/d/58350-XQQMS9BXXYQGX5C3 Tharayil, Gopal C. Kundu, Rohit Srivastava, Sabu Thomas, Chwee Teck Lim, Yanli Zhao, A Plasmonic Supramolecular Nanohybrid as a Contrast Agent for Site- Selective Computed Tomography Imaging of Tumor

4. Das, S.; Rakshit, S.; Datta, A. Mechanistic Insights into Selective Sensing of Pb2+ in Water by Photoluminescent CdS Quantum Dots. J. Phys. Chem. C 2021, 125 (28), 15396–1540

5. Ali, F.; Das, S.; Banerjee, S.; Maddala, B. G.; Rana, G.; Datta, A. Intense Photoluminescence from Cu-Doped CdSe Nanotetrapods Triggered by Ultrafast Hole Capture. Nanoscale 2021, 13 (33), 14228–14235.

6. Gogoi, H.; Maddala, B. G.; Ali, F.; Datta, A. Role of Solvent in Electron-Phonon Relaxation Dynamics in Core-Shell Au−SiO2 Nanoparticles. Chem Phys Chem 2021, 22 (21), 2201–2206.

7. Shally Sharma, Biomass-Derived Activated Carbon-Supported Copper Catalyst: An Efficient Heterogeneous Magnetic Catalyst for Base-Free Chan−Lam Coupling and Oxidations, ACS Omega, 6, 2021, Page no. 19529-19545

8. Prateek Bhardwaj, Jayant Sastri Goda, Venkatesh Pai, Pradip Chaudhari, Bhabani Mohanty, Trupti Pai, Komal Vishwakarma, Rahul Thorat, Tabassum Wadasadawala, Rinti Banerjee, Ultrasound augments on-demand breast tumor
radiosensitization and apoptosis through a tri-responsive combinatorial delivery theranostic platform, Nanoscale, 13 (2021), 17077-17092.

9. Bera, A.; Pathak, S. S.; Kotha, V.; Prasad, B. L. V. Lamellar Bimetallic Thiolates: Synthesis, Characterization, and Their Utilization for the Preparation of Bimetallic Chalcogenide Nanocrystals through Mechanochemical Grinding. Adv.
Mater. Interfaces 2021, 8 (23), 2100898.

10. Maurya, S. K.; Swaroop Pathak, S.; Panchakarla, L. S.; Singh, H. B. Synthesis and Self-Assembly of Amphiphilic Ferrocene-Selenopeptide Conjugates. European J. Org. Chem. 2022, 2022 (6), e202101363.

11. Pathak, S. S.; Panchakarla, L. S. A Large Area Flexible P-Type Transparent Conducting CuS Ultrathin Films Generated at Liquid-Liquid Interface. Appl. Mater. Today 2021, 24, 101152.

2022: 

1. Prateek Bhardwaj, Vikram Gota, Komal Vishwakarma, Venkatesh Pai, Pradip Chaudhari, Bhabani Mohanty, Rahul Thorat, Subhash Yadav, Murari Gurjar, Jayant Sastri Goda, Rinti Banerjee, Loco-regional radiosensitizing nanoparticles-
in-gel augments head and neck cancer chemoradiotherapy, Journal of Controlled Release, 343 (2022), 288-302.

2. Radhika Poojari, Bhabani Mohanty, Vijay Kadwad, Dayaram Suryawanshi, Pradip Chaudhari, Bharat Khade, Rohit Srivastava, Sanjay Gupta, Dulal Panda, Combinatorial cetuximab targeted polymeric nanocomplexes reduce PRC1 level
and abrogate growth of metastatic hepatocellular carcinoma in vivo with efficient radionuclide uptake, Nanomedicine: Nanotechnology, Biology and Medicine, Volume 41, 2022, 102529, https://doi.org/10.1016/j.nano.2022.102529.

3. Pranjali Yadav, Shubhra Chaturvedi, Samir Kumar Biswas, Rohit Srivastava, KamalakannanKailasam*, Anil Kumar Mishra*, and AsifkhanShanavas*,Biodegradable Protein-Stabilized Inorganic Nanoassemblies
for Photothermal Radiotherapy of Hepatoma Cells, , ACS Omega 2022

4. Single particle level dynamics of photoactivation and suppression of Auger recombination in aqueous Cu-doped CdS quantum dots, Sharmistha Das, Gourab Rana , Fariyad Ali and Anindya Datta, Nanoscale, 2023,15, 4469-4476

5. Carbon nanodot doped in polymer film: Plasmophore enhancement, catalytic amination and white-light generation, Farogh Abbas, Sagar Kumar, Surja Kanta Pal, Debashis Panda, Journal of Molecular Liquids, 2022, 347,118001

6. Enhancement of Antimycobacterial Activity of Rifampicin Using Mannose-Anchored Lipid Nanoparticles against Intramacrophage Mycobacteria Nishita Mistry, Rajdip Bandyopadhyaya, and Sarika Mehra, ACS Appl. Bio Mater. 2022, 5, 5779−5789

7. Yb3+-Doped Phenylethyl ammonium Lead Bromide 2D Layered Hybrid Perovskite for Near- Infrared Emission, Barnali Mondal, Athunya Poovathan, Dr. Tariq Sheikh, Prof. Angshuman Nag ChemNanoMat, 2022, 8, e202200104

8. Non-aqueous rechargeable calcium-ion batteries based on high voltage zirconium-doped ammonium vanadium oxide cathode Author links open overlay panelMd Adil, Ananta Sarkar, Supriya Sau, Divyamahalakshmi Muthuraj, Sagar Mitra
Journal of Power Sources 2022, 541,231669

9. Carbon coated titanium dioxide (CC-TiO2) as an efficient material for photocatalytic degradation. Rahul Kumar, Raveena Choudhary, Santa Kolay, O. P. Pandey, Kulvir Singh and Parag Bhargava Energy Adv., 2022, 1, 926-934

10. Comprehensive Study of Sodium Copper Hexacyanoferrate, as a Sodium-Rich Low-Cost Positive Electrode for Sodium-Ion Batteries Md. Adil, Supriya Sau, Pradeep Dammala, and Sagar Mitra, Energy Fuels 2022, 36, 7816−7828

11. In vivo efficacy & phantom imaging connote the theranostic potential of a drug-loaded lipid nanobubble. Authors Ekta Singh, Rinti Banerjee Journal of Drug Delivery Science and Technology 2022, 74,103568

12. Water-in-Salt Electrolyte-Based Extended Voltage Range, Safe, and Long-Cycle-Life Aqueous Calcium-Ion Cells Md. Adil, Arpita Ghosh, and Sagar Mitra, ACS Appl. Mater.Interfaces 2022, 14, 25501−25515

13. Sooting propensities of novel cage hydrocarbon propellants, Anand Sankaranarayanan, Nitesh Gupta, Sohan Lal Irishi N Namboothiri , Arindrajit Chowdhury , Neeraj Kumbhakarna, Fuel 2022, 329, 125437

14. Effect of dispersant added graphene nanoplatelets with diesel–Sterculia foetida seed oil https://ams.iitb.ac.in/d/103216-SPMCSWF5SNSUWME2 IITB-CF Budget 2023-24 4 biodiesel blends on diesel engine: engine combustion, performance and exhaust emissions, Gandhi Pullagura Srinivas Vadapalli ,Prasad V. V. S.& Kodanda Rama Rao
Chebattina, BioFuels 2022, 14, 2148876

15. Na2ZrFe(PO4)3 A Rhombohedral NASICON-Structured Material: Synthesis, Structure and Na Intercalation Behaviorc, Anil K. Paidi, Ankur Sharma, Vinod K. Paidi, Mani Pujitha Illa, Kug-Seung Lee, Sangsul Lee, Docheon Ahn, and Amartya Mukhopadhyay , Inorg. Chem.2023, 62, 4124−4135

16. Combinatorial cetuximab targeted polymeric nanocomplexes reduce PRC1 level and abrogate growth of metastatic hepatocellular carcinoma in vivo with efficient radionuclide uptake,Radhika Poojari, Bhabani Mohanty , Vijay Kadwad , Dayaram Suryawanshi ,Pradip Chaudhari , Bharat Khade , Rohit Srivastava , Sanjay Gupta , Dulal Panda PhD Nanomedi
cine: Nanotechnology, Biology and Medicine 2022, 41, 102529

17. Influence of Al3+-Gd3+ co-substitution on the structural, morphological, magnetic and optical properties of nickel ferrite nanoparticles Sanjay B. Gopale, Mangesh V. Khedkar, Swapnil A. Jadhav, Anil V. Raut, Sunil S. Karad, Govind D. Kulkarni & K. M. Jadhav, Journal of Materials Science: Materials in Electronics 2022, 33, 26544–26563.

18. Kinetic and Mechanistic Insight into the Surfactant-Induced Aggregation of Gold Nanoparticles and Their Catalytic Efficacy: Importance of Surface Restructuring Published as part of The Journal of Physical Chemistry virtual special issue “Kankan Bhattacharyya Festschrift”. Bhawna Saini, Laxmikanta Khamari, and Tushar Kanti Mukherjee, J. Phys.
Chem. B 2022, 126, 2130−2141

19. α-Synuclein Aggregation Intermediates form Fibril Polymorphs with Distinct Prion-like Propertiespanel,Surabhi Mehra , Sahil Ahlawat ,Harish Kumar ,Debalina Datta , Ambuja N avalkar , Nitu Singh , Komal Patel , Laxmikant Gadhe , Pradeep Kadu , Rakesh Kumar , Narendra N. Jha, Arunima Sakunthala , Ajay S. Sawner , Ranjith Padinhateeri , Jayant B. Udgaonkar , Vipin Agarwal , Samir K. Maji, Journal of molecular Biology 2022 434, 167761.

20. Synthetic Protocell as Efficient Bioreactor: Enzymatic Superactivity and Ultrasensitive Glucose Sensing in Urine, Bhawna Saini and Tushar Kanti Mukherjee, ACS Appl. Mater. Interfaces 2022, 14, 53462−53474

21. An Ultrasound-Responsive Theranostic Cyclodextrin-Loaded Nanoparticle for Multimodal Imaging and Therapy for Atherosclerosis. Sourabh Mehta, Viktoria Bongcaron, Tien K Nguyen, Yugandhara Jirwanka, Ana Maluenda, Aidan P G Walsh, Jathushan Palasubramaniam, Mark D Hulett, Rohit Srivastava, Alex Bobik, Xiaowei Wang, Karlheinz
Peter Small, 2022, 18, 202200967.
 

2023:

 1. Single particle level dynamics of photoactivation and suppression of Auger recombination in aqueous Cu-doped CdS quantum dots, Sharmistha Das, Gourab Rana , Fariyad Ali and Anindya Datta, Nanoscale, 2023,15, 4469-4476

1. The user has to collect TEM grids from FEG TEM lab.
2. The user has to come for TEM analysis with prepared sample on TEM grid.
3. The samples should be prepared on TEM grids of 3mm size and sample thickness should be less than 100nm for high resolution images.
4. Any query related to your FEG-TEM analysis can be emailed to fegtemlab@iitb.ac.in.
5. The samples should be dry and should withstand ultra-high vacuum.

1. Users should register online 
2. An appointment will be given as per queue and will be informed by email.
3. New users are requested to contact FEG TEM lab before registration.
4. At least 24 hrs prior information should be given to FEG TEM lab if users want to cancel/postpone the slot.

1. Internal user should register online
2. External Users should register online: https://saifora.iitb.ac.in/crnts/Online_Ext_Reg/Web_Portal_DST_SAIF/DST_SAIF_ExtOnlineExtProces_SAIFMumbai.html
3. An appointment will be given as per queue and will be informed by email.
4. New users are requested to contact FEG TEM lab before registration.