Dimethyl disulfide (DMDS) is a sulfur compounds with an unpleasant smell which is usually released from the oceans and seawaters and considered as an environmental problem for neighborhood areas. Therefore, it is of paramount importance to develop Electrochemical techniques, especially sensors, offers several advantages due to their simplicity, cost effectiveness, short response time, and the ability of continuous operation on site (in situ) which eliminates the needs for sampling and sample preparation prior to laboratory analysis [1]. The present study proposes a new electrochemical sensor for detection and determination of DMDS based on a graphene – chitosan modified glassy carbon. Graphene nanosheets and chitosan film were directly deposited onto a glassy carbon electrode through chronoamperomeric technique in two consecutive steps. It has been shown that chitosan acts as a protective layer which enhances the stability of graphene sensor. In order to obtain optimized operating conditions, the effects of various influential parameters on the response of the sensor were investigated. These parameters mainly include amount of the deposited graphene and chitosan, electrodeposition potentials and durations, and the pH of the sample solution. Square wave voltammetry has been used for quantitative determination of DMDS. Under optimum operating conditions, the sensor shows a linear response in the concentration range of 1×10-5 to 5×10-3 mol L-1 of DMDS. The sensor displays good reproducibility and long term stability. The proposed sensor was successfully applied to determine DMDS in various natural water samples.

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