Allotropy of selenium nanoparticles: Colourful transition, synthesis, and biotechnological applications
Miguel Ángel Ruiz-Fresneda, Lucian C. Staicu, Guillermo Lazuén‐López, Mohamed L. Merroun
Microbial Biotechnology
Abstract
Elemental selenium (Se<sup>0</sup> ) nanomaterials undergo allotropic transition from thermodynamically-unstable to more stable phases. This process is significantly different when Se<sup>0</sup> nanoparticles (NPs) are produced via physico-chemical and biological pathways. While the allotropic transition of physico-chemically synthesized Se<sup>0</sup> is fast (minutes to hours), the biogenic Se<sup>0</sup> takes months to complete. The biopolymer layer covering biogenic Se<sup>0</sup> NPs might be the main factor controlling this retardation, but this still remains an open question. Phylogenetically-diverse bacteria reduce selenium oxyanions to red amorphous Se<sup>0</sup> allotrope, which has low market value. Then, red Se<sup>0</sup> undergoes allotropic transition to trigonal (metallic grey) allotrope, the end product having important industrial applications (e.g. semiconductors, alloys). Is it not yet clear whether biogenic Se<sup>0</sup> presents any biological function, or it is mainly a detoxification and respiratory by-product. The better understanding of this transition would benefit the recovery of Se<sup>0</sup> NPs from secondary resources and its targeted utilization with respect to each allotropic stage. This review article presents and critically discusses the main physico-chemical methods and biosynthetic pathways of Se<sup>0</sup> (bio)mineralization. In addition, the article proposes a conceptual model for the resource recovery potential of trigonal selenium nanomaterials in the context of circular economy.
Extracted Claims
6 claims extracted from this paper into the knowledge graph
physico-chemically synthesized Se<sup>0</sup> transition fast
“While the allotropic transition of physico-chemically synthesized Se<sup>0</sup> is fast (minutes to hours), the biogenic Se<sup>0</sup> takes months to complete.”
biogenic Se<sup>0</sup> transition slow
“While the allotropic transition of physico-chemically synthesized Se<sup>0</sup> is fast (minutes to hours), the biogenic Se<sup>0</sup> takes months to complete.”
red Se<sup>0</sup> undergo allotropic transition
“Then, red Se<sup>0</sup> undergoes allotropic transition to trigonal (metallic grey) allotrope, the end product having important industrial applications (e.g. semiconductors, alloys).”