Long period grating based molecularly imprinted fiber optic sensor for the label-free detection of bisphenol A

• Published in: Optics and laser technology Vol. 176; p. 110932
• Main Authors: Sree Sanker, S.S., Thomas, Subin, Benjamin Varghese, P., Biswas, Palas, Jacob, Dhanya P., Nalini, Savitha, Madhusoodanan, K.N.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2024
• Subjects: Bisphenol A; Fiber optic sensor; Hydrogel; Long period grating; Molecular imprinting; Photopolymerization; Bisphenol A; Hydrogel; Photopolymerization; Molecular imprinting; Long period grating; Fiber optic sensor
• ISSN: 0030-3992
• DOI: 10.1016/j.optlastec.2024.110932

•Molecularly imprinted Long Period Grating (MILPG) sensor is developed for the selective and sensitive detection of Bisphenol A (BPA).•MAA-co-EGDMA based MILPG-BPA sensor is fabricated using photopolymerisation of hydrogel precursor on the Long Period Grating sensor.•The rebinding of the BPA molecules to the sensor causes the hydrogel to swell, leading to a significant shift in its resonant mode.•The sensor exhibits a low detection limit, rapid response time and selectivity for detecting BPA molecules.•The sensor offers high recovery, and label free detection of BPA. The molecularly imprinted fiber optic (MIFO) sensors are recognized for its reliability, sensitivity and selective analyte identification. In this study, we report a Long-Period Grating (LPG) based MIFO sensor developed for the label-free detection of Bisphenol A (BPA) in water samples. The sensor is fabricated by polymerizing hydrogel precursor containing BPA on the LPG, followed by etching BPA molecules. The rebinding of the BPA molecule to the molecularly imprinted long period grating Bisphenol A (MILPG-BPA) sensor causes the hydrogel to swell, leading to a peak shift in the LP07 resonant mode of the sensor. This shift is linear across BPA concentrations ranging from femto molar to nano molar range with a low limit of detection of 0.146 fM. The non-imprinted long period grating (NILPG) sensor showed no selective binding of the BPA molecule, underscoring the significance of the microenvironment established through molecular imprinting for effective sensing. The MILPG-BPA sensor exhibits high selectivity in detecting the BPA molecules among the potential interferents. Furthermore, it has a rapid response time and reusability, thus holding promise for a wide range of applications.