Research Projects

The proposed research aims to develop a cost-effective, label-free, liquid crystal (LC)-based point-of-care diagnostic (POCD) platform for the rapid detection of clinically significant biomolecules using birefringence changes under polarized microscopy and electrochemical impedance spectroscopy (EIS). The rationale of this work stems from the need of affordable, field-deployable biosensors that eliminate complex preparation, reagent labelling, and instrument-intensive protocols, especially for use in resource-limited settings and early diagnosis. Traditional biomolecule detection methods are often time-consuming, expensive, and inaccessible to many users, particularly in rural or under-resourced clinical environments. LCs—owing to their anisotropic nature and high sensitivity to external interfacial stimuli—offer a versatile platform for molecular detection by exhibiting detectable changes in alignment and optical texture in the presence of target analytes. Building on our successful preliminary demonstration of a penicillin detection platform using a 5CB LC flow-cell design (which achieved 100 nM sensitivity and costs less than ₹100), this proposal aims to extend and generalize the sensing concept to detect medically vital molecules: arginase (marker for cellular homeostasis; normal range 1-30 ng/mL, target sensor LOD 20 ng/mL), CA-125 (ovarian cancer biomarker; normal range less than 35 ng/mL, target sensor LOD 20 ng/mL), TSH (thyroid function; normal range 0.5-5 uIU/mL, target sensor LOD 4 uIU/mL) and dopamine (neurological function; normal range less than 0.1 ng/mL, target sensor LOD 0.1 ng/mL). The central hypothesis is that the molecular interaction between the LC layer and each target biomolecule (or a byproduct of a biochemical reaction) induces measurable distortions in LC alignment, manifesting as distinct birefringence patterns or impedance signatures that correlate with analyte concentration. For example, in the case of enzymatic reactions (such as arginase or penicillinase), the release of H⁺ ions will trigger LC realignment, while direct biomolecular binding (e.g., CA-125, dopamine, etc.) at immobilized recognition sites will also cause measurable anisotropic changes. Our experimental framework includes fabricating flow-based optical cells using low-cost substrates (e.g., PMMA, uncoated TEM grids), optimizing LC doping formulations, immobilizing biomolecule-specific enzymes or ligands on the grid, and conducting millifluidic assays under polarized light and EIS analysis. In this project, low cost (origami based paper) polarised microscope (similar to foldscope, which is already market available) and / or low cost EIS-enabled portable potentiostat (HELPStat) would be integrated, for quick on-site detection of the LC birefringence patterns and impedance profiles. Detection thresholds, selectivity, sensitivity limits, possible interferences and reproducibility (confidence limit greater than 0.9) will be established for each analyte using the developed sensor. The expected life of the sensor with the proposed accuracy, will be at least more than 6 months. This project outcome will culminate in the development of a single-use diagnostic kit that enables rapid and inexpensive field testing for diseases including ovarian cancer, renal failure, thyroid dysfunction, and Alzheimer’s disease for early diagnosis. The platform aligns with affordable healthcare and rural diagnostics, with translational potential in household POCD kits and low-resource healthcare centres. Furthermore, the sensing strategy is broadly adaptable to other analytes, positioning this work at the forefront of biosensor innovation. Overall, this project represents a significant step toward low cost access to biochemical diagnostics, with high societal impact and scientific novelty in the domain of anisotropic materials-based sensing platforms.