https://doi.org/10.1140/epjs/s11734-026-02305-y
Regular Article
Optical anisotropic studies on biomolecular interfacial interaction in liquid crystal cell for tumor biomarker detection
1
CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, 110012, New Delhi, India
2
Academy of Scientific and Innovative Research (AcSIR), 201002, Ghaziabad, Uttar Pradesh, India
3
Department of Mechanical Engineering, Delhi Technological University, Shahbad Daulatpur, Bawana Road, 110042, New Delhi, Delhi, India
a
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Received:
27
October
2025
Accepted:
30
March
2026
Published online:
8
April
2026
Abstract
An ultra-sensitive, label-free optical aptasensor utilizing liquid crystal (LC) has been fabricated for detecting platelet-derived growth factor-BB (PDGF-BB), a tumor biomarker. The sensing platform has been built by incorporating nematic LC (4-cyano-4´-pentyl biphenyl) into a confined area of a transmission electron microscopic (TEM) grid which is positioned within a 4 mm diameter well made on a polyacrylic sheet sandwiched between a silane coated glass slide and a polydimethylsiloxane (PDMS) stamp having a micro-channel inlet for sample insertion. The optical response associated with LC orientation at the LC-aqueous interface was examined for PDGF detection using PDGF-BB-specific DNA aptamer in the presence of surfactant under a polarized optical microscope (POM) and the corresponding grayscale area of the POM images was quantified using image-J software. The LC-aptasensor exhibited a linear optical response in normalized grayscale area (%) with the lowest detection limit of 0.58 pM over a wide concentration range of 1 pM–100 nM PDGF-BB with a sensitivity of 14% change in optical response per decade of PDGF-BB in human serum. The spectroscopic and zeta potential characterization was carried out to delineate the sensing mechanism of aptamer interaction with PDGF-BB antigen in the presence of surfactant molecules reflecting its outcome on the optical anisotropic response of LC orientation at the LC-aqueous interface. A distinct optical response of the LC aptasensor obtained with PDGF-BB antigen in comparison to the possible interferents showed its high specificity for PDGF-BB and its potential application in early-stage detection of diseases associated with both elevated and reduced levels of PDGF-BB in human serum.
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© The Author(s), under exclusive licence to EDP Sciences, Springer-Verlag GmbH Germany, part of Springer Nature 2026
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
