Extracellular Polymeric Substances Govern the Surface Charge of Biogenic Elemental Selenium Nanoparticles

Rohan Jain, Norbert Jordan, Stephan Weiss, Harald Foerstendorf, Karsten Heim, Rohit Kacker, René Hübner, Herman Kramer, Eric D. van Hullebusch, François Farges, Piet N. L. Lens

Research output: Contribution to journalArticlepeer-review

158 Scopus citations


© 2014 American Chemical Society. The origin of the organic layer covering colloidal biogenic elemental selenium nanoparticles (BioSeNPs) is not known, particularly in the case when they are synthesized by complex microbial communities. This study investigated the presence of extracellular polymeric substances (EPS) on BioSeNPs. The role of EPS in capping the extracellularly available BioSeNPs was also examined. Fourier transform infrared (FT-IR) spectroscopy and colorimetric measurements confirmed the presence of functional groups characteristic of proteins and carbohydrates on the BioSeNPs, suggesting the presence of EPS. Chemical synthesis of elemental selenium nanoparticles in the presence of EPS, extracted from selenite fed anaerobic granular sludge, yielded stable colloidal spherical selenium nanoparticles. Furthermore, extracted EPS, BioSeNPs, and chemically synthesized EPS-capped selenium nanoparticles had similar surface properties, as shown by ζ-potential versus pH profiles and isoelectric point measurements. This study shows that the EPS of anaerobic granular sludge form the organic layer present on the BioSeNPs synthesized by these granules. The EPS also govern the surface charge of these BioSeNPs, thereby contributing to their colloidal properties, hence affecting their fate in the environment and the efficiency of bioremediation technologies.
Original languageEnglish (US)
Pages (from-to)1713-1720
Number of pages8
JournalEnvironmental Science & Technology
Issue number3
StatePublished - Jan 21 2015
Externally publishedYes

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The authors thank Dr. Graciella Gil-Gonzalez (KAUST, Saudi Arabia) for insightful discussion, Ferdi Battles (UNESCO-IHE, The Netherlands) for the Nanosizer and acid–base titration experiments, Berend Lolkema (UNESCO-IHE, The Netherlands) for TOC, TN, and 3D EEM analysis, Elfi Christalle (Helmholtz-Zentrum, Dresden-Rossendorf, Germany) for SEM-EDXS measurements, and Purvi Jain (Utrecht University, The Netherlands) for DNA measurements.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.


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