A disposable sensor for diagnosing leptospirosis

Work done in the lab of Dr. K Sudhakara Prasad at Nano Material Research Lab, Yenepoya Research Centre, Yenepoya Deemed to be University, Karnataka

About author

Sapna Kannan is currently in the final stage of her doctoral studies working under the guidance of Dr. Arun A.B. and Dr. K Sudhakara Prasad at Yenepoya Deemed to be University, Mangalore. She completed her Masters in Biotechnology and Biochemical Engineering from Sree Buddha College of Engineering, Kerala. She was initially recruited for an ICMR-funded project, after that she was awarded ICMR Senior Research Fellowship to work on her doctoral studies on the development of biosensors for the detection of Leptospirosis. Recently, she was awarded ICMR-Research Associate Fellowship to continue her research on development and clinical validation of ultrasensitive POCT platforms for Leptospirosis in patient samples. Additionally to her work as a passionate researcher, Sapna enjoys painting and photography.

Interview

How would you explain your research outcomes to the non-scientific community?

Leptospirosis or rat fever, is a re-emerging disease that threatens the health of millions of people worldwide and is one of the most serious public health problems. Mostly occurs in India during the monsoon season. Leptospirosis is under reported usually due to lack of accurate and rapid diagnostic methods, and is frequently misdiagnosed since the symptoms are similar to other febrile illnesses such as dengue, malaria, scrub typhus etc. As a result, conventional methods of diagnosing leptospirosis such as MAT (Macroscopic agglutination test), IgM ELISA, culture and PCR are time-consuming, require skilled personnel, are costly, and are limited to reference labs.Leptospirosis must be diagnosed early and accurately in order to provide prompt and effective treatment, which may save patients’ lives.

We developed a highly sensitive electrochemical sensor (e-LipL32) for diagnosis of leptospirosis by detecting the presence of LipL32 protein in patient serum samples. LipL32 is a major surface membrane protein and plays a key role in leptospirosis diagnosis. We used simple paper based electrodes for fabrication of the immunosensor, which was decorated with gold nanoparticles and glutathione monolayers for making the immune-sandwich platform with selective monoclonal antibodies. In addition, we employed carbon nanotubes for signal enhancement. The sensor detected LipL32 protein concentration as low as 348 fg/mL with high selectivity. Moreover, the sensor utility when validated with 20 samples from patients suspected of having leptospirosis, as well as other febrile illnesses was found to be successful in differentiating the infected and non-infected subjects. Compared to conventional techniques, the sensor provided rapid and accurate results. We believe the e-LipL32 could be used to detect leptospirosis at an early stage, where sophisticated instruments and lab facilities are unavailable.

How do these findings contribute to your research area?

The Point-of-Care Testing (POCT) platform developed here, aids in the sensitive detection of leptospirosis. We hope the miniaturization and integration with a handheld device could make the test more simple and could be used in hospitals and rural health centres. We are also looking for simpler tests and further validation studies with larger cohort samples.

“The Point-of-Care Testing (POCT) platform developed here, aids in the sensitive detection of leptospirosis.”

What was the exciting moment during your research?

One of the most exciting moments during our research was observing positive results for leptospirosis confirmed patient samples with our developed e-LipL32 sensor and while differentiating the infected and non-infected ones.

What do you hope to do next?

Our next step is to validate e-LipL32 sensors in a larger cohort of patients. In future, I aspire to develop affordable health-care POCT platforms for infectious disease by utilizing cutting edge nanotechnology, microbiology and biotechnology techniques together, which I have learnt successfully during my doctoral studies.

Where do you seek scientific inspiration from?

In research, inspiration is the key element that you require on a daily basis. I believe curiosity to know more, is the major motivation that drives and inspires people to work in research. This is the main reason for me to be in scientific research.

How do you intend to help Indian science improve?

Indian science has progressed considerably in recent years. However, there is still a lack of multidisciplinary approaches, which is hindering the translation of basic research. Through interdisciplinary research and collaborations with researchers and clinicians, I aim to solve the healthcare challenges that we are facing in the area of infectious diseases. Also being a woman in science, I observe very less participation of women in Indian academia, research and industry, hence would like to sensitize my colleagues and friends to support women researchers in the country.

Reference

Sapna K, Sonia J, Shim YB, Arun AB, Prasad KS*. Au Nanoparticle-Based Disposable Electrochemical Sensor for Detection of Leptospirosis in Clinical Samples. ACS Applied Nano Materials. 2022. https://pubs.acs.org/doi/abs/10.1021/acsanm.2c01978

Copy Editor

Anjali Mahilkar

Postdoctoral Fellow at University of Michigan

Anjali is an evolutionary biologist working as a postdoctoral researcher in the department of Ecology and Evolutionary Biology at University of Michigan, Ann Arbor. Her research interests mainly lie in understanding the relationship between natural selection, adaptation and drift in deciding the evolutionary fates of biological functions as well as of whole organisms. She has a PhD from IIT Bombay where her research focused on understanding the process of speciation. Anjali also has her Masters from IIT Kanpur and Bachelor’s from NIT Raipur. She also had short work stints at Dr. Reddy’s Institute of Life Science and at a Central University in Chhattisgarh. She is interested in science communication and volunteers for several organizations towards the same. Although not an avid reader, she likes to read fiction in her free time.

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