title: Multienzymatic amperometric biosensor based on gold and nanocomposite planar electrodes for glycerol determination in wine.
abstract: Amperometric biosensors based on gold planar or nanocomposite electrode containing multiwalled carbon nanotubes for determination of glycerol were developed. The biosensors were constructed by immobilization of a novel multienzyme cascade consisting of glycerol kinase/creatine kinase/creatinase/sarcosine oxidase/peroxidase between a chitosan "sandwich." A measuring buffer contained adenosine 5'-triphosphate (ATP), creatine phosphate, and an artificial electrochemical mediator ferrocyanide. The currents proportional to glycerol concentration were measured at working potential of -50 mV against Ag/AgCl reference electrode. The biosensors showed linearity over the ranges of 5-640 μM and 5-566 μM with detection limits of 1.96 and 2.24 μM and sensitivities of 0.80 and 0.81 nA μM(-1), respectively. Both types of biosensors had a response time of 70s. The biosensors demonstrated satisfactory operational stability (no loss of sensitivity after 90 consecutive measurements) and excellent storage stability (90% of the initial sensitivity after 15 months of storage at room temperature). The results obtained from measurements of wines correlated well with those obtained with an enzymatic-spectrophotometric assay. The presented multienzyme cascade can be used also for determination of triglycerides or various kinase substrates when glycerol kinase is replaced by other kinases.
authors: Institute of Biochemistry, Nutrition, and Health Protection, Slovak University of Technology, 812 37 Bratislava, Slovak Republic. rasto.monosik@gmail.com
authors: Rastislav
authors: R
authors: Monošík
authors: Dana
authors: D
authors: Ukropcová
authors: Miroslav
authors: M
authors: Streďanský
authors: Ernest
authors: E
authors: Šturdík
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004800:Enzymes, Immobilized; D005990:Glycerol / Q000032:analysis*; D006046:Gold; D053768:Metal Nanoparticles; D009097:Multienzyme Complexes; D053761:Nanocomposites; D037742:Nanotubes, Carbon; D013053:Spectrophotometry; D014920:Wine / Q000032:analysis*
chemical_list: D004800:Enzymes, Immobilized; D009097:Multienzyme Complexes; D037742:Nanotubes, Carbon; D006046:Gold; D005990:Glycerol