Characterization of graphite electrodes modified with laccase from Trametes versicolor and their use for bioelectrochemical monitoring of phenolic compounds in flow injection analysis

Amperometric Detection of Hydroquinone and Homogentisic Acid with Laccase Immobilized Platinum Electrode

“…Although exact reason for the improved sensitivity of the sensor is not fully understood several effects may be included such as the high affinity of the enzyme for the substrates, the increased catalytic rate of the enzyme, and the better mobility of the substrate in the enzyme layer. 27 Besides laccases, other enzymes were also immobilized for HQ detection, and the converted relative sensitivities are as follows: 100%, 125%, 70% and 4000% for this study, CDH (FIA mode), 23 20 or that of GOD immobilized sensor, i.e. upper limit of 4 µM.…”

“…20 The sensitivity of the sensor reported here combined with these reported sensitivities can be sequentially converted to relative ones of 100%, 27%, 112% and 89%. Taken into account of the fact that FIA (flow injection analysis) mode were employed in case of graphite electrode (φ 3.05 mm) the sensitivity reported here may be said highly improved.…”

“…30 The detection limit can be estimated to be 50 nM (S/N = 3) with the background noise of about 5 nA. The detection limit of T. versicolor laccase immobilized sensor for HQ is 440 nM 20 or 600 nM, 34 and that of CDH immobilized sensor or GOD immobilized sensor is 3.5 nM 23 or 1 nM. 22 In spite of the similar sensitivities among the sensor reported here, CDH sensor and GOD sensor the obtained detection limit in this study is relatively high, which may be due to the relatively high background noise possibly caused by the strong modification condition.…”

“…for biosensor method, although the instrumental analysis is accurate, specific and sensitive it often requires delicate and timeconsuming sample pretreatment prior to the analysis and requires utilization of heavy equipment, therefore, they are inappropriate for massive screening. 12,18 In reported biosensor methods, for detection of HQ enzymes such as laccase (T. versicolor), 19,20 glucose dehydrogenase (GDH, A. calcoaceticus), 21 glucose oxidase (GOD, Aspergillus) 22 and cellobiose dehydrogenase (CDH, P. chrysosporium), 23 etc. were used, and for detection of HGA enzymes such as laccase (T. versicolor), 19 homogentisate dioxygenase (A. nidulans), 12 etc.…”

Hybrid Film Biosensor for Phenolic Compounds Detection

“…In this mechanism the electron donor (substrate) penetrates the active site of the enzyme where it is oxidized in a single electron oxidation step often producing electrochemically active compound (possibly a radical) that it turn can be re-reduced at the electrode surface in a mediated electron transfer step. This creates an electron-shuttle process between the electrode and the laccase providing the basis for reduction of molecular oxygen by mediated electron transfer at the enzymatic electrode (Haghighi et al, 2003). In particular, several biosensors based on tyrosinase were developed for determination of phenols Dzyadevych eta al., 2002).…”