Dr. Navakanta Bhat of Centre for Nano Science and Engineering, Indian Institute of Science

In this talk, I will describe our fascinating journey in the last few years, traversing through scientific discovery, engineering innovation, entrepreneurial venture and manufacturing scale-up to create one of its kind multi-analyte point of care diagnostic device for diabetes and its complications. The device is currently capable of performing 5 blood tests (Hb, HbA1c, Serum Albumin, Glycated Albumin, Glucose) and 3 urine tests (Microalbuminuria, Urine Creatinine and Urine ACR), using electrochemical bio-sensing technology (www.pathshodh.com). Based on my experience, I will also discuss the challenges involved in translating the scientific discovery into product to create societal impact. According to IUPAC definition, Biosensor is a self-contained receptor-transducer device, unlike a bio-analytical system in pathology labs. The “receptor” should be selective to a specific biomolecule and robust against variations in ambient conditions (humidity, temperature etc). There has been a lot of emphasis in using enzymes and antibodies as receptors. While they are extremely selective, their stability is less than satisfactory for point of care diagnostic applications. Despite the large number of publications in Biosensors literature, the commercialization has alarmingly lagged behind. Several critical reviews have stressed the need to invent new receptors to fast track the deployment of Biosensors ("Probes, Sensors, and Labels: Why is Real Progress Slow?" Angew. Chem. Int. Ed. 2013, 52, 9864 – 9865). We explore novel receptors, based on chemical ligands and metal ions, which are highly stable, as opposed to enzymes and antibodies. The identification of the receptors is based on careful analysis of the journey of a given biomolecule inside the human body from its synthesis to degradation. For instance, the electrochemical detection of albumin has been elusive, since there is no redox active metal centre in its structure. albumin, an abundant plasma protein, is also called as “molecular taxi” in the human body. It can bind to variety of substances including fatty acids, drugs, metal ions etc. We note that albumin has the highest binding affinity with Copper with an association constant of 1.6x1016 M-1. By embedding dry copper chemistry using a copper salt (CuCl2, CuSO4), we demonstrate highly reliable and robust electrochemical detection technique for serum albumin. We then extend this by combining it with boronic affinity principle, to demonstrate the first of its kind technique for glycated albumin detection using disposable strips. On similar lines, we utilize aza-heterocyclic compounds as chemical ligands for the detection of hemoglobin. Although hemoglobin is metalloprotein, with redox active iron centre, the electrochemical detection is impeded. This is due to hydroxyl coordination of iron centre, resulting in the formation of dimers and tetramers, thus blocking the diffusion controlled redox process. Using pyridine and imidazole, hemoglobin is converted into pyridine/imidazole-hemichrome, by replacing hydroxyl coordination of iron centre with amine coordination. This results in unhindered electrochemical detection of hemoglobin. We then extend this to measure glycated hemoglobin, using boronic affinity principle.

Biography:

Professor Navakanta Bhat received his Ph.D. in Electrical Engineering from Stanford University, in 1996. Then he worked at Motorola’s Advanced Products R&D Lab in Austin, TX until 1999. He joined IISc in 1999, where he is currently a Professor and Chairperson in Centre for Nano Science and Engineering. His current research is on Nanoelectronics and Sensors. He has more than 200 publications and 20 patents. He was instrumental in creating the National Nanofabrication Centre (NNfC) at IISc, benchmarked against the best university facilities in the world. He is the recipient of IBM Faculty award, Swarnajayanti Fellowship (DST) and Outstanding Research Investigator award (DAE). He is a Fellow of INAE. He was the Editor of IEEE Transactions on Electron Devices, during 2013-2016. He is the member of Board of Governors of IEEE Electron Devices Society. He was a member of the National Innovation Council in Nanoelectronics and member of the committee setup by PSA’s office (Govt. of India), to recommend strategies to develop semiconductor manufacturing ecosystem in India. He was the Chairman of Infrastructure and Human Resource Development committee under the National Program on Micro and Smart Systems. He is the founder and promoter of a startup called “PathShodh Healthcare”, which builds point-of-care diagnostic devices for diabetes and its complications.

Email:

Address:Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore, Karnataka, India, 560012

Dr. Navakanta Bhat of Centre for Nano Science and Engineering, Indian Institute of Science

Biography:

Email:

Address:Bangalore, Karnataka, India

Dr. Navakanta Bhat of Centre for Nano Science and Engineering, Indian Institute of Science

Biography:

Email:

Address:Bangalore, Karnataka, India