Highly Sensitive Fluorescent pH Microsensors Based on the Ratiometric Dye Pyranine Immobilized on Silica Microparticles

08.08.2021

Authors: Anil Chandra, Saumya Prasad, Helena Iuele, Francesco Colella, Riccardo Rizzo, Eliana D'Amone, Giuseppe Gigli, Loretta L. del Mercato

Chemistry. 2021 Sep 20; 27(53):13318-13324 - Epub 2021 Jul 26
DOI: https://doi.org/10.1002/chem.202101568

Abstract: Pyranine (HPTS) is a remarkably interesting pH-sensitive dye that has been used for plenty of applications. Its high quantum yield and extremely sensitive ratiometric fluorescence against pH change makes it a very favorable for pH-sensing applications and the development of pH nano-/microsensors. However, its strong negative charge and lack of easily modifiable functional groups makes it difficult to use with charged substrates such as silica. This study reports a methodology for noncovalent HPTS immobilization on silica microparticles that considers the retention of pH sensitivity as well as the long-term stability of the pH microsensors. The study emphasizes the importance of surface charge for governing the sensitivity of the immobilized HPTS dye molecules on silica microparticles. The importance of the immobilization methodology, which preserves the sensitivity and stability of the microsensors, is also assessed.

Keywords: HPTS; fluorescence; microparticles; pH sensors; ratiometric sensing

Front Cover: Chemistry-A European Journal, Volume27, Issue53, September 20, 202, Pages 13275-13275
DOI: https://doi.org/10.1002/chem.202102673
Download PDF : Link

Cover Profile: Chemistry-A European Journal, Volume27, Issue53, September 20, 202, Pages 13275-13275
DOI: https://doi.org/10.1002/chem.202102674
Download PDF : Link


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