Applications of electrochemistry in studies of the oxidation chemistry of central nervous system indoles

Influence of different biological environments on the stability of serotonin detection on carbon-based electrodes

“…Following oxidation 5-HT forms a radical that reacts with another 5-HT molecule forming dimers and trimers. These species then eventually polymerise on the electrode surface reducing the stability and sensitivity of the electrode for further measurements [16,17].…”

Studies of the behavior of 5-hydroxyindole-3-acetamide at a solid electrode

“…Nevertheless, the presence of (V) and (IX) strongly indicates that these compounds do exist in the electrolyzed solution and only part of them are converted to quinones. Such behavior is not uncommon and has been reported during oxidation of large numbers of dimeric indoles [32,33]. It is well Scheme 2. documented that the formation of quinones takes place at relatively low concentrations (lM) of the starting materials as reported during oxidation of 5-hydroxytryptamine [32].…”

Artificial enzyme-based catalytic sensor for the electrochemical detection of 5-hydroxyindole-3-acetic acid tumor marker in urine

“…The nature of the oxidation products catalytically obtained was inferred by comparison to the electrochemical behavior of related indoles previously investigated [25] and HPLC-MS identification [22]. The first reduction peak at E p = 0 V is believed to be the reduction of quinone-imine species into 5-hydroyindole derivatives, whereas the smaller wave at −0.15 V is assigned to oquinone groups which typically appear at lower potentials [25]. We have used the faradaic current arising from the reduction of quinone-imine species measured by DPV to determine the rate of the catalytic oxidation of 5-HIAA.…”