A novel colorimetric and ratiometric pH sensor with a notably large Stokes shift for sensing extremely alkaline solution

Chemometric-Assisted Litmus Test: One Single Sensing Platform Adapted from 1–13 to Narrow pH Ranges

“…Moving to the main features of these sensors and limiting the investigation to the most recent papers, different pH-sensitive molecules have been proposed, among which the most common are commercial pH indicators [ 1 , 4 , 5 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ], novel pH-sensitive compounds [ 1 , 4 , 5 , 17 , 18 ], natural dyes [ 1 , 4 , 19 , 20 , 21 , 22 , 23 ], and luminescent probes [ 1 , 3 , 4 , 24 , 25 , 26 , 27 ]. On the other hand, unlike pH papers, these sensors can exploit different solid substrates and, consequently, anchor mechanisms such as physical entrapment, [ 1 , 3 , 4 , 5 , 11 , 19 , 20 , 23 ] sol–gel synthesis [ 1 , 4 , 10 , 12 , 13 , 14 , 15 , 16 , 24 ] or covalent immobilization [ 1 , 4 , 5 ], hence offering a fully tunable device depending on the final application.…”

Highly Reversible “Off‐On‐Off” Dual‐channel Fluorescence Probe Based on Amino Pyrazole and Phenothiazine for Sensing Extremely Alkaline Solution

“…Compared with traditional methods, fluorescence technology has become an attractive tool for environmental detection and biological imaging because of its easy visualization and operation, low cost, excellent selectivity, and sensitivity. [7][8][9] More importantly, it is particularly useful when it needs to be mainly located in single cell components and environmental water samples, because it can accurately feed back real-time information about cell and environmental water samples. In the past few years, as a focus in the field of sensing analytes, many pH sensors have been developed in the fields of environment, biomedicine and industry, which have the advantages of high chemical selectivity, biocompatibility and high sensitivity.…”

A SERS pH sensor for highly alkaline conditions and its application for pH sensing in aerosol droplets

“…19,20 SERS also performs well in microenvironmental pH sensing applications, due to its high sensitivity and because there is no interference from photobleaching. [21][22][23][24][25][26][27] As a rapid and nondestructive technology, 28,29 SERS with probes can realize single-particle pH analysis, which has strong potential in the eld of pH sensing. 30,31 Gong et al directly measured the pH of micron-sized droplets with SERS-activated pH paper.…”