Development of micro-optrodes using sol-gel immobilisation

Miniaturised fibre optic chemical sensors continue to be developed in a number of research laboratories around the world. Such fibre optic sensors originate from work originally undertaken during the development of nanometric aperture probes used in scanning near-field optical microscopes. The probes can be converted to sensors for highly localised chemical measurements by attaching the appropriate chemical indicators to the probe tips. The term `optrode´ has been widely used to describe a sensor utilising optical detection methods, and the authors introduce the term `micro-optrode´ to describe their miniaturised fibre optic sensors, which possess a high spatial resolution. The authors present recent results obtained in their laboratories where they have constructed such sensors using chemically sensitised sol-gel glasses