Synthesis and Characterization of L-cysteine-modified ZnSe:Co/ZnSe Quantum Dots

Biologically Derived Metal–Cysteine Coordination Complexes Crosslink Carboxylated Nitrile Rubber and Enable Room Temperature Self-Healing, Stretchability, and Recyclability

“…The cysteine amino acid’s amine group is protonated first when the pH is decreased, then the thiol group, and finally the carboxylic acid groups. The synthesis of the metal–cysteine (M­(Cys) 2 , where M = Zn or Ni) complex was always prepared at the pH value of 7–9 . Because the metal ion has no particular affinity for any of the coordination sites on cysteine, changing the pH value can affect how metal ions (Zn or Ni) attach to cysteine.…”

“…Because of the complexation of amine groups and the metal atoms, the peak of l -cysteine, which was previously at 1573 cm –1 (N–H bending), has been moved to the higher wavenumber at 1590 cm –1 . The COO stretching vibration of metal–cysteine complexes ,, is thought to be responsible for the band at 1398 cm –1 . In the FTIR spectra of metal–cysteine complexes, the band at 637 cm –1 (C–S stretching) of l -cysteine has totally vanished.…”

“…The synthesis of the metal−cysteine (M(Cys) 2 , where M = Zn or Ni) complex was always prepared at the pH value of 7−9. 56 Because the metal ion has no particular affinity for any of the coordination sites on cysteine, changing the pH value can affect how metal ions (Zn or Ni) attach to cysteine. Therefore, we have synthesized the metal−cysteine coordination complexes at the pH value of 7−9.…”

Mid-Infrared Emission of Transition Metal Co2+-Doped ZnSe Nanocrystals at Room Temperature via Hydrothermal Preparation

“…Recently, TM 2+ -doped ZnSe nanomaterials have attracted increasing attention because of their high luminescence quantum efficiency, high optical gain with low threshold, and their potential applications in display devices, biomedical labeling, and lasers. − ZnSe plays an important role in studying semiconductor nanocrystals . In fact, over the past few years, researchers have focused on the visible luminescence properties of ZnSe nanomaterials doped with Ni 2+ , Co 2+ , , Fe 2+ , , and Mn 2+ . − Little attention has been paid to the IR fluorescence properties of TM 2+ -doped ZnSe nanocrystals. Studies − that investigated II–VI nanocrystals with transition metal ions (such as Ni 2+ , Co 2+ , Fe 2+ , and Cr 2+ ) obtained by laser ablation of bulk polycrystalline samples have demonstrated optical characteristics in the mid-IR spectral region, and mid-IR luminescence in the spectral range of 2–6 μm and laser oscillation of Cr 2+ ions , under direct excitation have been achieved.…”

“…10−14 ZnSe plays an important role in studying semiconductor nanocrystals. 15 In fact, over the past few years, researchers have focused on the visible luminescence properties of ZnSe nanomaterials doped with Ni 2+ , 16 Co 2+ , 17,18 Fe 2+ , 19,20 and Mn 2+ . 21−23 optical characteristics in the mid-IR spectral region, and mid-IR luminescence in the spectral range of 2−6 μm and laser oscillation of Cr 2+ ions 25,26 under direct excitation have been achieved.…”