Aggregation induced emission of an anionic tetraphenylethene derivative for efficient protamine sensing

• Published in: Journal of molecular liquids Vol. 315; p. 113625
• Main Authors: Pandey, Shrishti P., Jha, Pamela, Singh, Prabhat K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-10-2020
• Subjects: Aggregation induced emission; Fluorescence sensor; Protamine sensor; Tetraphenylethylene derivative; Tetraphenylethylene derivative; Fluorescence sensor; Aggregation induced emission; Protamine sensor
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2020.113625

Protamine, an arginine rich polycationic peptide, is the only clinically approved antidote of Heparin and has been successfully used in reversing the action of Heparin in case of Heparin overdose, a situation which can have fatal outcomes. Therefore, developing sensors for Protamine is of uttermost importance in clinical diagnosis. However, only limited reports are available on optical detection of Protamine, since it is relatively difficult to detect Protamine due to its composition, which is devoid of aromatic amino acids. In the present contribution, we describe a fluorescence turn-on sensing scheme for Protamine which utilizes the phenomenon of aggregation induced emission of an anionic derivative of tetraphenylethene, i.e. sodium 1,2-bis[4-(3-sulfonatopropoxyl)phenyl]-1,2-diphenylethene (BSPOTPE) on interaction with Protamine. The interaction between BSPOTPE and Protamine has been thoroughly investigated using various photophysical techniques, which include, ground state absorption, steady-state and time-resolved emission spectroscopy, and molecular docking calculations. The interaction of BSPOTPE with Protamine leads to large modulation in its photophysical properties, with an enhancement of ~70-fold in emission intensity and significant modulation in excited-state lifetime. Apart from being simple and selective, the present sensor system is highly sensitive for Protamine with a LOD of 47 pM in aqueous solution. Importantly, BSPOTPE is a commercially available probe molecule which provides freedom from the tedious and time-consuming protocols to develop synthetic probe molecules for sensor applications, which normally serves as an impediment for real-life applications.
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•A Tetraphenylethene derivative (BSPOTPE) shows turn-on emission towards Protamine.•BSPOTPE shows high selectivity and sensitivity for Protamine with a LOD of 47 pM.•BSPOTPE operates through aggregation induced emission on the Protamine surface.•BSPOTPE-Protamine complex can be utilized for sensing Heparin.