Optical and electrochemical sol-gel sensors for inorganic species

The use of sol-gels as a sensing matrix for the development of unique sensing strategies is discussed. Sol-gels offer almost limitless possibilities for sensing substrates due to the variety of physical properties that can be obtained by altering a number of discussed fabrication conditions and techniques. By careful consideration of the sensing requirements, novel detection methods have been developed for a variety of analytes and applications. Here, sol-gels have been used to monitor pH at the extreme ends of the scale ([H+] = 1–11 M and [OH−] = 1–10 M) and in mixed solvent/solute systems using dual sensing approaches. The use of ligand-grafted sol-gel monoliths for optical determination of metal ion species is also discussed. The electrochemical determination of Cr(VI) by electrodeposited sol-gel modified electrodes is also presented.