TY - JOUR
T1 - Synthesis of pH Sensitive Dual Capped CdTe QDs
T2 - Their Optical Properties and Structural Morphology
AU - Daramola, Olamide Abiodun
AU - Siwe Noundou, Xavier
AU - Nkanga, Christian Isalomboto
AU - Tseki, Potlaki Foster
AU - Krause, Rui Werner Maçedo
N1 - Publisher Copyright:
© 2020, Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2020/5/1
Y1 - 2020/5/1
N2 - We herein report five different types of thiol dual capped cadmium tellurite quantum dots (CdTe QDs) namely glutathione-mercapto-propanoic acid (QD 1), glutathione-thiolglycolic acid (QD 2), L-cysteine-mercapto-propanoic acid (QD 3), L-cysteine- thiol-glycolic acid (QD 4) and mercapto-propanoic acid-thiol-glycolic (QD 5). Dual-capped CdTe QDs were prepared using a one pot synthetic method. Cadmium acetate and sodium tellurite were respectively used as cadmium and tellurium precursors. Photo-physical properties of the synthesized QDs were examined using UV-Vis and photoluminescence spectroscopy while structural characterization was performed by means of transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. The influence of pH on QD characteristics (fluorescence intensity) was studied using phosphate and citrate buffers and continuous titration with HCl (0.1 N). UV-vis and photoluminescence spectra exhibited sharp absorption band edge with high intensities and improved colloidal stability. All the QDs were found to be in nano-size rang. TEM analysis revealed the presence of spherical nanoparticles while FTIR evidenced successful dual-capping of QDs. Upon pH changes, QDs 3 and 4 demonstrated more remarkable variations in fluorescence intensity than QDs 1 and 2. The pH-sensitivity of these QDs represents a promising feature for further development of potential theranostic nano-devices.
AB - We herein report five different types of thiol dual capped cadmium tellurite quantum dots (CdTe QDs) namely glutathione-mercapto-propanoic acid (QD 1), glutathione-thiolglycolic acid (QD 2), L-cysteine-mercapto-propanoic acid (QD 3), L-cysteine- thiol-glycolic acid (QD 4) and mercapto-propanoic acid-thiol-glycolic (QD 5). Dual-capped CdTe QDs were prepared using a one pot synthetic method. Cadmium acetate and sodium tellurite were respectively used as cadmium and tellurium precursors. Photo-physical properties of the synthesized QDs were examined using UV-Vis and photoluminescence spectroscopy while structural characterization was performed by means of transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. The influence of pH on QD characteristics (fluorescence intensity) was studied using phosphate and citrate buffers and continuous titration with HCl (0.1 N). UV-vis and photoluminescence spectra exhibited sharp absorption band edge with high intensities and improved colloidal stability. All the QDs were found to be in nano-size rang. TEM analysis revealed the presence of spherical nanoparticles while FTIR evidenced successful dual-capping of QDs. Upon pH changes, QDs 3 and 4 demonstrated more remarkable variations in fluorescence intensity than QDs 1 and 2. The pH-sensitivity of these QDs represents a promising feature for further development of potential theranostic nano-devices.
KW - Dual-capped CdTe quantum dots
KW - Photo-physical properties
KW - pH-sensitivity
UR - http://www.scopus.com/inward/record.url?scp=85082312700&partnerID=8YFLogxK
U2 - 10.1007/s10895-020-02526-x
DO - 10.1007/s10895-020-02526-x
M3 - Article
C2 - 32219628
AN - SCOPUS:85082312700
SN - 1053-0509
VL - 30
SP - 557
EP - 564
JO - Journal of Fluorescence
JF - Journal of Fluorescence
IS - 3
ER -