Synthesis, Characterization, and MRI Properties of Cysteamine-Stabilized Cadmium Zinc Selenide (Cd(Zn)Se) Quantum Dots for Cancer Imaging
Purpose We aimed at facile synthesis of Cd(Zn)Se quantum dots (QDs) and immobilizing it with contrast agent for its applicability as bimodal imaging probe. The imaging probe should have both fluorescence property and magnetic property, so that it can be used in both fluorescence imaging system and magnetic resonance imaging (MRI). Procedure Cd(Zn)Se quantum dots (QDs) were synthesized using cysteamine hydrochloride as a stabilizing agent by wet chemical reactions. The synthesized QDs were characterized for its structural properties using X-ray and electron diffractions, microstructural properties using transmission electron microscopy and optical properties using UV-visible spectrophotometer, fluorescence, fluorescence lifetime, and Fourier-transformed infrared spectroscopy. Further, gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) immobilized the Cd(Zn)Se quantum dots at different concentration and were examined for its applicability as a contrast agent for magnetic resonance imaging (MRI). Results The maximum absorbance was measured at 433 nm using UV-visible double-beam spectrophotometer. The maximum emission was observed at 552 nm and the fluorescence lifetime study estimated the full-width half-maximum as 1.189 ns. The Fourier-transformed infrared (FTIR) spectroscopy confirmed the presence of amine group on the surface of the synthesized quantum dots. The relaxation time was also calculated for Gd-DTPA-immobilized Cd(Zn)Se for different concentrations of Gd-DTPA. Conclusion Our observed experimental results explore the possibility of utilizing Gd-DTPA-immobilized Cd(Zn)Se quantum dots for bimodal probe in recognizing cancer (tumour) cells for optical (fluorescence) and MR imaging.
KeywordsSemiconductor nanoparticles Cd(Zn)Se quantum dots Cysteamine hydrochloride Gadolinium—diethylenetriaminepentaacetic acid MRI contrast agent Bimodal imaging
The author would like to thank Dr. T. Prakash, Assistant Professor, NCNSNT, University of Madras, Guindy Campus, Chennai and Director-Research, Chettinad Academy of Research and Education, and Head of the department, Department of Radiology and Imaging, Chettinad Hospitals and Research Institute, Kelambakkam, Chennai 603103, India. The author also thanks MR Technologist, Chettinad Hospitals and Research Institute, Sophisticated Analysis and Instrumentation Facility (SAIF), Indian Institute of Technology Madras (IITM), Chennai 600036, India, National Centre for Nanoscience and Nanotechnology (NCNSNT), University of Madras, Chennai 600025, India and Centre for ocean research, Sathyabama University for helping us to utilize various characterization techniques.
Conflict of Interest
The authors declare that they have no conflict of interest.