Alginate nanofibers with an average diameter of 75 nrn have been prepared by the electrospinning process. In addition, the spinnability of the solutions in the presence of the gold precursor HAuCl4 was investigated. At low concentrations of HAuCl4 well-formed nanofibers were produced, whereas as its concentration increases the nanofibrous mats present an increased number of bead-like defects. Herein, the in situ preparation of gold nanoparticles (Au NPs) is discussed since sodium alginate (SA) acts as the reducing agent and a mechanism is proposed in order to explain the bead-effect as well as the surface morphology of the alginate fibers decorated with Au NPs. (C) 2016 Elsevier Inc. All rights reserved.