Inspired by the broad range activities of indoles, we explored the antioxidant and electrochemical behavior of indole-3-carbaldehyde (I3C). The compound was first tested for cytotoxicity followed by the evaluation of its antioxidant activity using thiobarbituric acid-reactive species (TBARs). The selected indole was then investigated by several voltammetric techniques to gain insights about proposing its antioxidant action mechanism. Kinetics of the electrode reaction was probed by cyclic voltammetry experiments, which led to the determination of diffusibility constant and heterogeneous electron transfer rate constant. The feasibility of the redox event of 13C was judged from the thermodynamic parameters evaluated by observing the influence of temperature on the anodic response of the analyte. Square wave voltammetry (SWV) was employed for ensuring the reversible or irreversible nature of the oxidation reaction of I3C. Differential pulse voltammetry (DPV) was applied for the determination of number of electrons and protons involved in oxidation of the analyte. Moreover, DPV and SWV were used for the sensitive detection of I3C at bare and gold nanoparticles modified glassy carbon electrode. On the basis of voltammetric findings an oxidation mechanism supported by computational results was proposed with the objective of unravelling the antioxidant behavior of a representative of indoles. (C) 2016 The Electrochemical Society. All rights reserved.