Tunable photoluminescence properties of selenium nanoparticles: biogenic versus chemogenic synthesis

Abstract

<jats:title>Abstract</jats:title><jats:p>Various technological and biomedical applications rely on the ability of materials to emit light (photoluminescence [PL]), and, among them, metal nanoparticles (NPs) and semi-conductor Quantum Dots (QDs) represent ideal candidates as sensing probes and imaging tools, portraying better PL features than conventional organic dyes. However, the knowledge of PL behavior of semiconductor NPs – i.e., selenium; SeNPs – is still in its infancy, especially for those synthesized by microorganisms. Considering the essential role played by biogenic SeNPs as antimicrobial, anticancer, and antioxidant agents, or food supplements, their PL properties must be explored to take full advantage of them as eco-friendly and versatile tools. Here, PL features of SeNPs produced by the Se-tolerant <jats:italic>Stenotrophomonas maltophilia</jats:italic> SeITE02 strain, compared with chemogenic ones, are investigated, highlighting the PL dependency on the NP size. Indeed, PL emission shifted from indigo-blue (emission wavelength <jats:italic>λ</jats:italic><jats:sub>em</jats:sub> 400–450 nm) to green-yellow (<jats:italic>λ</jats:italic><jats:sub>em</jats:sub> 480–570 nm) and orange-red (<jats:italic>λ</jats:italic><jats:sub>em</jats:sub> 580–700 nm) for small (ca. 50 nm) and big (ca. 100 nm) SeNPs respectively, revealing the versatility of an environmental bacterial isolate to synthesize diverse PL probes. Besides, biogenic SeNPs show PL lifetime comparable to those of the most used fluorophores, supporting their potential application as markers for (bio)imaging.</jats:p>

Size Tuning, Phase Stabilization, and Anticancer Efficacy of Amorphous Selenium Nanoparticles: Effect of Ion-Pair Interaction, −OH Functionalization, and Reuse of RTILs as Host Matrix

“…Undoubtedly, such differences in the absorption profiles of NPs clearly indicate the influence of the intrinsic environments of these RTILs on the formation of Se NPs with significantly different optical properties and morphological features. Various researchers in the recent past have also reported a strong correlation between the optical properties of Se NPs and their morphologies. ,,− ,, …”

“…Various methodologies could be found in the literature regarding the synthesis of Se NPs. Some of the common strategies are solvothermal, radiation-based, biogenic, laser ablation, sonochemical, and microwave-assisted. ,− However, there are very few reports showing fine control over the morphology as well as phase of Se NPs. ,, In addition, the application of such protocols is further limited by the low stability of α-Se NPs (especially in colloidal form) undergoing rapid phase transformation. Moreover, in the current scenario, the main focus is toward developing such protocols that are green and sustainable for catering to commercial requirements.…”

Selenium nanoparticles: a review on synthesis and biomedical applications

“…In general, depending upon the intensity of a particular peak, one can estimate the type of Se formed. Piacenza et al 107 suggested the use of biologically synthesized SeNPs in bio-imaging. They synthesized SeNPs from yeast extract which exhibited a strong photoluminescence emission in the blue-red region of the visible spectrum and a luminescence lifetime comparable to those of mostly used fluorophores.…”

Biogenic Selenium Nanoparticles: A Fine Characterization to Unveil Their Thermodynamic Stability

“…cultures from dark yellow to orange-red (Figure 1). This phenomenon is due to the development of exciton resonance within Se atoms, which determines the rising of unique optical properties as a function of the size and shape of SeNMs, as well as their surrounding environment [26]. Micrococcus sp.…”