The synthesis and development of new metal-polymer nanocomposites is essential in various fields of science and technology. Here, we report a facile synthesis of silver-polyindole nanocomposite at an immiscible liquid/liquid interface using silver oxide as an oxidizing agent. The composite is characterized using different spectroscopic, microscopic, thermogravimetric and XRD analysis and are also compared with synthesized polyindole. This is the first report on the synthesis of the silver-polyindole nanocomposite apart from the demonstration of nanomolar sensing ability of Ag-PIn towards dopamine. The proposed Ag-PIn sensor exhibits a high sensitivity with a linear range of 40 nM to 12 mM. © 2018 Elsevier Ltd.