This is the first comprehensive review on methods and materials for use in optical sensing of
pH values and on applications of such sensors. The Review starts with an introduction that …

The sol–gel technology is being increasingly used for the development of optical sensors
and biosensors, due to its simplicity and versatility. By this process, porous thin films …

Nanofibres functionalised with pH-sensitive dyes could greatly contribute to the
development of stimuli-responsive materials. However, the application of biocompatible …

A new colour-based disposable sensor array for a full pH range (0–14) is described. The pH
sensing elements are a set of different pH indicators immobilized in plasticized polymeric …

Evanescent wave absorption based PCS (plastic clad silica) fiber optic pH sensor is
constructed by encapsulation of indicator dyes in the heterogeneous inorganic hybrid silica …

Thermally stable phenolphthalein encapsulated silica–titania nanomatrix is fabricated by sol–
gel method for optochemical pH sensing. The particle size∼ 56–121 nm is obtained with …

A neural network multivariate calibration is used to predict the pH of a solution in the full-
range (0–14) from hue (H) values coming from imaging an optical pH sensor array based on …

Long-term stable ratiometric fluorescent optical pH sensors (optodes) based on double sol–
gel silica layers are prepared with the first layer embedding two types of quantum dots (QDs) …

An in-depth study was conducted to determine the influence of some important parameters
to produce a pH colorimetric sensor characterized by long-term stability, lack of leaching …

Owed to rapid responsive pH sensing attributes, the zinc-supported Silica-titania (Z/ST)
nanocomposite is synthesized by the sol-gel method. Three distinct pH dyes such as …