Prof Mahesh Kumar of IIT Jodhpur

Clean water is vital for flourishing human, animal and plant life on earth but with the advent of rapid industrialization and usage of several chemicals for developing certain technologies and products there is an increasing concern over health implications caused by their disposal to the natural waters, lakes and rivers. The toxicity of those chemical compounds needs to be ascertained before it gets mixed up with our drinking water source. Lead poisoning is a severe environmental issue that affects people all around the world. The presence of these ions in drinking water pose a great risk as their higher concentrations may lead to immediate death while lower concentrations can effect central nervous system, kidney related disorders, skin related ailments and cancer. AlGaN/GaN heterojunctions have potential for the chemical and biochemical sensing application including industrial processes, pharmaceutical, medical research, water analysis industries and development. The AlGaN/GaN high electron mobility transistor is good candidate for chemical sensing due to its capability of being stable in harsh environments, low toxicity, high conductivity sensitivity to surface conditions, and functionality of ungated surfaces. Different technological approaches were selected for heavy metal detection such as Anodic stripping Voltammetry (ASV), Colorimetric Detection, Electrochemical approach, ISFET but all these approaches have certain drawbacks such as lack of portability, highly expensive set up, requirement of reference electrode and incapable to operate under harsh environmental conditions and at elevated temperatures .The standard permissible limits in drinking water have been set by World health organization (WHO), and the Environmental protection agency (EPA) for these heavy metal ions, above which the water is assumed to be toxic and not suitable for drinking. This led to an urge for developing an cost effective, mechanically robust and highly miniaturized device for onsite detection of heavy metal ions in drinking water. The functionalization of graphitic carbon nitride is used to produce a new, extremely sensitive AlGaN/ GaN high electron mobility transistor (HEMT) sensor for the detection of lead (Pb2+) ions. The synthesised g-C3N4 was functionalized on an Au gated AlGaN/ GaN HEMT, and the device's sensing capability was assessed using electrical measurements. The g-C3N4 based AlGaN/ GaN HEMT sensor shows much higher sensitivity and lower detection limit. The measured detection level is far lower than the World Health Organization's (WHO) standard drinking water guideline values. We also show that the sensing response is highly quick owing to the availability of 2-D electron gas (2DEG) and very sensitive due to the change in gate potential utilizing AlGaN/GaN HEMT theory. The reduction of Pb2+ ions on the g-C3N4 surface, which creates negative redox potential at the gate terminal while exposing the functionalized HEMT to Pb2+ ions, causes the decrease in drain current. Talk will focus on various type of heavy metal ion sensors.

Biography:

Prof. Mahesh Kumar is Professor at Indian Institute of Technology (IIT) Jodhpur. He has received INSA Medal for Young Scientists-2014 by Indian National Science Academy, the MRSI Medal-2016 by Materials Research Society of India, DAE-Young Achiever Award-2016 by BRNS, Research Excellence Award 2020 by IIT Jodhpur and Friedrich Wilhelm Bessel Research Prize by The Alexander von Humboldt Foundation, Germany. He is recipient of the Brain Pool Program-2022 by Korean National Research Foundation, Fulbright-Nehru Academic and Professional Excellence Fellowships-2021; The Royal Society International Exchange Award-2021; JSPS Invitation Fellowship-2021, PIFI Visiting Scientist fellowship-2021 by Chinese Academy of Science; Duo-India Professor Fellowship-2020, Bhaskara Advanced Solar Energy Fellowship-2018 and INSA-DFG International Bilateral Exchange Award-2015. Recently INAE awarded him Abdul Kalam Technology Innovation National Fellowship 2022. He is also Editorial Board member of Nanotechnology, IEEE Sensors Journal, Bulletin of Materials Science and Nano Express. He is also Fellow of Royal Society of Chemistry and Institute of Physics. He is founding Member and served as Chair of Indian National Young Academy of Sciences. He has published more than 170 research articles. His research interests are focused on 2D materials, Nanomaterials, Sensors, Semiconductor materials and devices.

Email:

Address:IIT Jodhpur, , Jodhpur, India