New near‐infrared emissions and energy transfer in Er³⁺‐doped MgAl layered double hydroxides

Abstract

A series of Er 3+-doped magnesium aluminium layered double hydroxides (Er 3+-doped, MgAl-LDHs) with different Mg 2+ /(Al 3+ +Er 3+) molar ratios were synthesized using the hydrothermal method. Compositional and structural analyses suggest that the Er 3 +-doped MgAl-LDHs kept a hexagonal structure while the Mg 2+ /(Al 3+ +Er 3+) molar ratio was at 1.0-4.1. The downconverted emission spectra of the Er 3+-doped MgAl-LDHs showed a red emission at 650 nm and strong infrared emissions at 720, 780, and 850 nm. These infrared emissions were hardly observed in previous downconverted emission spectra of Er 3+-doped materials. In the analysis of the Er 3+ energy levels and in relevant published literature, the energy transfer diagram for Er 3+-doped in MgAl-LDHs is described, and infrared emissions at 720, 780, and 850 nm may be attributed to 4 F 7/2 ! 4 I 13/2 , 2 H 11/2 ! 4 I 13/2 , and 4 S 3/2 ! 4 I 13/2 transitions of Er 3+ , respectively. Er 3+-doped MgAl-LDHs could have potential application as marking and targeting agents in the processes for drug delivery in consideration of the strong near-infrared Er 3+ emissions, as well as the special layered structure of MgAl-LDH.

Photophysical Characterization of Er3+ doped and Er3+/Nd3+ co-doped Gd(OH)3 Nanocrystals: the Impact of Hexamethylenetetramine utilization for Morphology Engineering

“…The OHhas high phonon energy (~3350 cm -1 ) which increases the non-radiative transition and quenches photoluminescence intensity [83] In this section, the goal is to analyze the possible (potential) applications of the synthesized Gd(OH)3 nanorods. The following three (3) properties are considered important requirements for a material to be used for deep tissue in vivo imaging such as in MRI and PDT ( [88,89]; it should i. be nontoxic ii.…”

Photophysical Characterization of Er3+ doped and Er3+/Nd3+ co-doped Gd(OH)3 Nanocrystals: the Impact of Hexamethylenetetramine utilization for Morphology Engineering

“…The OHhas high phonon energy (~3350 cm -1 ) which increases the non-radiative transition and quenches photoluminescence intensity [83] In this section, the goal is to analyze the possible (potential) applications of the synthesized Gd(OH)3 nanorods. The following three (3) properties are considered important requirements for a material to be used for deep tissue in vivo imaging such as in MRI and PDT ( [88,89]; it should i. be nontoxic ii.…”

Trends in Layered Double Hydroxides‐Based Advanced Nanocomposites: Recent Progress and Latest Advancements

“…[ 183 ] Several reports demonstrated the polymer‐coated LDHs for wound dressing application through delivering drugs, such as cefotaxime, [ 184 ] ciprofloxacin, [ 185 ] silver sulfadiazine, [ 97d ] enoxacin, [ 186 ] and naproxen. [ 98 ] Similarly, these LDHs with interesting attributes presented their enormous potential in various biomedical applications, such as biosensing for non‐enzymatic glucose sensing (Figure 14D), [ 15d ] DNA extraction, [ 187 ] and photoluminescence, [ 188 ] among others. [ 189 ] However, these fields of biomedicine using LDHs and their innovative nanocomposites with organic polymers and inorganic constructs need further efforts to represent efficiency, selectivity, and reusability attributes.…”