Continuous and selective measurement of oxytocin and vasopressin using boron-doped diamond electrodes.
The electrochemical detection of oxytocin using boron-doped diamond (BDD) electrodes was studied. Cyclic voltammetry of oxytocin in a phosphate buffer solution exhibits an oxidation peak at +0.7 V (vs. Ag/AgCl), which is attributable to oxidation of the phenolic group in the tyrosyl moiety. Furthermore, the linearity of the current peaks obtained in flow injection analysis (FIA) using BDD microelectrodes over the oxytocin concentration range from 0.1 to 10.0 μM with a detection limit of 50 nM (S/N = 3) was high (R(2) = 0.995). Although the voltammograms of oxytocin and vasopressin observed with an as-deposited BDD electrode, as well as with a cathodically-reduced BDD electrode, were similar, a clear distinction was observed with anodically-oxidized BDD electrodes due to the attractive interaction between vasopressin and the oxidized BDD surface. By means of this distinction, selective measurements using chronoamperometry combined with flow injection analysis at an optimized potential were demonstrated, indicating the possibility of making selective in situ or in vivo measurements of oxytocin.
Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan.
Kai
K
Asai
Department of Chemistry, Faculty of Mathematics and Science, University of Indonesia, Kampus UI Depok, Jakarta 116424, Indonesia.
Tribidasari A
TA
Ivandini
Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan.|JST-ACCEL, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan.
Yasuaki
Y
Einaga
D015374:Biosensing Techniques; D001895:Boron / Q000737:chemistry; D004566:Electrodes; D057230:Limit of Detection; D010084:Oxidation-Reduction; D010121:Oxytocin / Q000737:chemistry / Q000302:isolation & purification*; D014667:Vasopressins / Q000737:chemistry / Q000302:isolation & purification*
D014667:Vasopressins; D010121:Oxytocin; D001895:Boron