Enhanced chemiluminescence biosensor for the determination of phenolic compounds and hydrogen peroxide

The enhanced chemiluminescence (CL) reaction of the luminol–H2O2–horseradish peroxidase (HRP) system with immobilized HRP using microencapsulation in a sol–gel matrix has been used to develop a biosensor for p-iodophenol, p-coumaric acid, 2-naphthol and hydrogen peroxide. The detection limits obtained for p-iodophenol, p-coumaric acid and 2-naphthol were 0.83 μM, 15 and 48 nM, respectively. Direct enzyme immobilization onto the end of the optical fibre permits the construction of a remote enhanced CL biosensor. This remote biosensor has been applied to hydrogen peroxide assay (detection limit 52.2 μM and relative standard deviation 4.7% for n=4) and the results have been compared with the biosensor developed in cuvette.