High-performance liquid chromatographic determination of phenols using a tyrosinase-based amperometric biosensor detection system

Abstract

A glassy carbon electrode was modified by co-immobilization of tyrosinase and a conducting poly( 1-vinylimidazo1e)-based osmium polymer on its surface. The ability of this biosensor to function as a detector for the HPLC determination of phenolic compounds, such as p-aminophenol, phenol, p-cresol, catechol and p-chlorophenol, was then assessed. The mobile phases investigated were binary mixtures of methanol and phosphate buffer. The effects of operational parameters, such as the concentrations of the electrode-modifying compounds, i.e., the osmium polymer and the cross-linking agent, poly(ethy1ene glycol), the mobile phase flow rate, the working potential and the biosensor's short-term stability were investigated and optimized. The biosensor exhibited a 100-200-fold improvement in sensitivity and detection limit when compared with a UV/VIS spectrophotometric detector. The amperometric phenol biosensor was able to detect catechol, phenol, p-cresol, m-cresol and four other phenolic compounds in cigarette filter tips.

Graphite-teflon-tyrosinase composite electrodes for the monitoring of phenolic compounds in predominantly non aqueous media

“…Tyrosinase has also been immobilized in a thin layer of silica sol-gel on a carbon paste electrode, which retained a 50 % of its activity for some phenolic compounds after fifteen days of storage in phosphate buffer at 4 °C [10]. Moreover, a tyrosinase-based amperometric biosensor detection system, in which the enzyme was coimmobilized with a conducting poly(1-vinylimidazole)-based osmium polymer, was applied to the high-performance liquid chromatographic determination of phenols [11].…”

Biosensors for environmental applications: Future development trends

“…The combination of these two methods can enable identification of molecules that are not detectable separately by either method [133]. Components are thus identified by both functional recognition and separation retention time [134,135]. A review by Fishman et al presented examples and principles of combining chemical separation with biosensor detection using living systems, whole cells, membrane receptors, enzymes, and immunosensors [133].…”

Electroanalytical Flow Measurements–Recent Advances

“…In recent years, several articles on the use of amperometric biosensors with immobilized tyrosinase for selective detection of phenolic compounds in HPLC were reported. The use of a GC electrode modified by co-immobilization of tyrosinase and poly(1-vinylimidazole)-based osmium polymer provides a sensitivity in detection of some phenolics 100-to 200-fold greater than UV/vis spectrophotometry [169]. For the same purpose biosensors with tyrosinase immobilized on microporous gold electrode via chemisorbed layer of thioctic acid and poly-lysine [170] and in carbon paste [171] have been employed.…”