Highly sensitive fluorescent pH microsensor based on the ratiometric dye pyranine immobilized on silica microparticles

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 development of pH nano/microsensors. However, its strong negative charge and lack of easily modifiable functional groups makes it difficult to be used with charged substrates such as silica. This study reports a noncovalent HPTS immobilization methodology on silica microparticles that considers the retention of pH sensitivity as well as long term stability of the pH microsensors. The study emphasizes on importance of surface charge for governing the sensitivity of the immobilized HPTS dye molecules on silica microparticles. Importance of methodology of immobilization that preserves the sensitivity as well as stability of the microsensors is also assessed.

arXiv comment8 pages, 4 figures, 1 table

References in corpus (3)

• Probing the pH microenvironment of mesenchymal stromal cell cultures on additive-manufactured scaffolds
• Ratiometric Organic Fibers for Localized and Reversible Ion Sensing with Micrometer-Scale Spatial Resolution
• Optical and magnetic resonance imaging approaches for investigating the tumour microenvironment: state-of-the-art review and future trends

Cited by in corpus (4)

• A pH Sensor Scaffold for Mapping Spatiotemporal Gradients in Three Dimensional In Vitro Tumour Models
• Facile One Pot Synthesis of Hybrid Core-Shell Silica-Based Sensors for Live Imaging of Dissolved Oxygen and Hypoxia Mapping in 3D cell models
• A Fluorescent Ratiometric Potassium Sensor Based on IPG4-Silica Microparticles for Selective Detection and Fluorescence Imaging of Potassium Cations
• A 3D Pancreatic Cancer Model with Integrated Optical Sensors for Noninvasive Metabolism Monitoring and Drug Screening