Tunable emission in surface passivated Mn-ZnS nanophosphors and its application for Glucose sensing

Abstract

The present work describes the tunable emission in inorganic-organic hybrid NPs which can be useful for optoelectronic and biosensing applications. In this work, Mn-ZnS nanoparticles emitting various colors, including blue and orange, were synthesized by simple chemical precipitation method using chitosan as a capping agent. Earlier reports describe that emission color characteristics in nanoparticles are tuned by varying particle size and with doping concentration. Here in this article tunable emission has been achieved by varying excitation wavelength in a single sample. This tunable emission property with high emission intensity was further achieved by changing capping concentration keeping host Mn-ZnS concentration same. Tunable emission is explained by FRET mechanism. Commission Internationale de l'Eclairage (CIE) chromaticity coordinates shifts from (0.273, 0.20) and (0.344, 0.275) for same naocrystals by suitably tuning excitation energy from higher and lower ultra-violet (UV) range. Synthesized nanoparticles have been characterized by X-ray diffraction, SEM, HRTEM, UV-Visible absorption and PL spectroscopy for structural and optical studies. Using tunable emission property, these highly emissive nanoparticles functionalized with biocompatible polymer chitosan were further used for glucose sensing applications. Copyright 2012 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License.

Synthesis of fluorescent core-shell nanomaterials and strategies to generate white light

“…6 A 1 ) of Mn 2þ close to 590 nm. 23,28,29 It is because the NPs have high surface to volume ratio that surface defects can quench the emission by providing the alternative path of nonradiative relaxation. The formation of the shell (inorganic capping) over the core not only passivates these defects but at the same time can also satisfy cationic and anionic dangling bonds, thereby blocking the alternative path for nonradiative transition.…”

“…Earlier we have shown tunable emission in the inorganic-organic hybrid NPs by FRET (Foster Resonance Energy Transfer) mechanism. 23,27 CIE chromaticity coordinates shifts from (0.27, 0.20) to (0.34, 0.27) for chitosan capped and Mn doped ZnS QDs by suitably tuning excitation energy in the higher and lower ultra-violet (UV) range. These materials can be used for bio-sensing applications, but the photometric properties of these NPs were not superior.…”

“…23 The Zinc Sulphide (ZnS) core was doped with Manganese (Mn) and Copper (Cu) separately. The shell of ZnS was formed over the doped core.…”

Design Considerations and Assays for Hemocompatibility of FDA-Approved Nanoparticles

“…For example, in bulk, gold typically reflects a yellowish color; but in nanoscale, the reflectance wavelength of gold can be varied from the visible to the infrared by changing the number of atoms. 28 Examples of inorganic NPs of interest include metallic NPs (gold, silver, or iron oxide 29 ), semiconductor NPs [30][31][32] (quantum dots made from CdSe, CdTe, silicon), nanophosphors, ceramic NPs, and more (►Fig. 1D and 1E).…”

Effect of Ag on structural, optical and luminescence properties of ZnS nanoparticles synthesized by microwave-assisted chemical route

“…Semiconductor nanomaterials of II-VI group have gained much attention since last 20 years due to their unique optical and luminescence properties which can be used in the devices related to various fields such as optoelectronics, sensors and photoluminescence [1][2][3][4]. These materials are becoming more prominent nowadays as the properties which they possess can be enhanced as well as altered by the doping process.…”