Researchers at the Indian Institute of Technology (IIT) Guwahati, led by Prof. Dipankar Bandyopadhyay from the Centre for Nanotechnology and Department of Chemical Engineering, have developed a nanoscale approach to improve the detection of cholesterol and triglycerides. By integrating Surface-Enhanced Raman Scattering (SERS) with bimetallic nanostructures, the team has achieved high-fidelity detection of these critical biomarkers in human blood.
The research findings, published in the journal Biosensors and Bioelectronics, are authored by Dr Mitali Basak, Prof Dipankar Bandyopadhyay, and Prof. Harshal B. Nemade. The study focuses on addressing the limitations of traditional lipid profile tests, which often require laboratory settings and are not suited for point-of-care applications.
Cholesterol and triglycerides are essential metabolic biomolecules that significantly influence cardiovascular health. High-density lipoproteins (HDL) and low-density lipoproteins (LDL) transport cholesterol to cells for metabolic activities. An imbalance between HDL and LDL can lead to arterial plaque formation, hypertension, and other cardiovascular conditions. Similarly, triglycerides, packaged as very low-density lipoproteins (VLDL), are transported to cells but, when elevated, can result in coronary artery disease, pancreatitis, and type 2 diabetes.
Timely detection and monitoring of cholesterol and triglyceride levels are critical for mitigating these health risks. The research team’s technique combines nanotechnology with molecular detection to enhance diagnostic precision and pave the way for point-of-care solutions.
The innovative approach employs SERS-active bimetallic nanostructures, specifically silver-shelled gold nanorods. These nanorods enable plasmonic resonance hybridisation of silver and gold, producing augmented spectral resolutions compared to pure silver or gold nanorods. By linking these nanorods to Raman-active receptors and immobilising them with cholesterol oxidase and lipase enzymes, the researchers achieved concurrent detection of varying concentrations of cholesterol and triglycerides.
Prof. Dipankar Bandyopadhyay highlighted the potential impact of the research: “With the recent advent of low-cost and portable Raman spectroscopy devices, there is a possibility of using these sensors for real-time monitoring of HDL, LDL, VLDL, and TGA at patients’ sites. This could help mitigate cardiovascular diseases before their onset or at an acute stage. Further, indigenising such high-precision sensors will enable the development of our own auto-analysers, which are currently imported.”
The research validated the performance of the silver-gold nanorods (Ag–Au NRs) through experiments and advanced simulations. The coupling of silver and gold enhanced localised surface plasmon resonance (LSPR) properties, amplifying signals 20 to 50 times more effectively than gold nanorods alone. This enhanced light interaction makes the nanorods particularly advantageous for nano-enabled SERS applications.
This development represents progress in molecular diagnostics, improving the precision and sensitivity of cholesterol and triglyceride testing. By enabling earlier detection of cardiovascular diseases at the point of care, the research has the potential to significantly impact healthcare outcomes.