pH-Controlled fluorescence switching in water-dispersed polymer brushes grafted to modified boron nitride nanotubes for cellular imaging

Saban Kalay; Yurij Stetsyshyn; Volodymyr Donchak; Khrystyna Harhay; Ostap Lishchynskyi; Halyna Ohar; Yuriy Panchenko; Stanislav Voronov; Mustafa Çulha

doi:10.3762/bjnano.10.233

pH-Controlled fluorescence switching in water-dispersed polymer brushes grafted to modified boron nitride nanotubes for cellular imaging

Beilstein J Nanotechnol. 2019 Dec 10:10:2428-2439. doi: 10.3762/bjnano.10.233. eCollection 2019.

Authors

Saban Kalay¹, Yurij Stetsyshyn², Volodymyr Donchak², Khrystyna Harhay², Ostap Lishchynskyi², Halyna Ohar², Yuriy Panchenko², Stanislav Voronov², Mustafa Çulha¹

Affiliations

¹ Department of Genetics and Bioengineering, Yeditepe University, Atasehir, 34755 Istanbul, Turkey.
² Lviv Polytechnic National University, 12 S. Bandery, 79013 Lviv, Ukraine.

Abstract

pH-Switchable, fluorescent, hybrid, water-dispersible nanomaterials based on boron nitride nanotubes (BNNTs) and grafted copolymer brushes (poly(acrylic acid-co-fluorescein acrylate) - P(AA-co-FA)) were successfully fabricated in a two-step process. The functionalization of BNNTs was confirmed by spectroscopic, gravimetric and imaging techniques. In contrast to "pure" BNNTs, P(AA-co-FA)-functionalized BNNTs demonstrate intense green fluorescence emission at 520 nm. Under neutral or alkaline pH values, P(AA-co-FA)-functionalized BNNTs are highly emissive in contrast to acidic pH conditions where the fluorescent intensity is absent or low. No increase in the absorption was observed when the suspension pH was increased from 7 to 10. The functionalized BNNTs are easily taken up by human normal prostate epithelium (PNT1A) and human prostate cancer cell lines (DU145) and are suitable for further evaluation in cellular imaging applications.

Keywords: boron nitride nanotubes; cellular imaging; fluorescence; pH switching; polymer brushes; surface modification.