Highly luminescent-paramagnetic nanophosphor probes for in vitro high-contrast imaging of human breast cancer cells.
Highly luminescent-paramagnetic nanophosphors have a seminal role in biotechnology and biomedical research due to their potential applications in biolabeling, bioimaging, and drug delivery. Herein, the synthesis of high-quality, ultrafine, europium-doped yttrium oxide nanophosphors (Y(1.9)O(3):Eu(0.1)(3+)) using a modified sol-gel technique is reported and in vitro fluorescence imaging studies are demonstrated in human breast cancer cells. These highly luminescent nanophosphors with an average particle size of ≈6 nm provide high-contrast optical imaging and decreased light scattering. In vitro cellular uptake is shown by fluorescence microscopy, which visualizes the characteristic intense hypersensitive red emission of Eu(3+) peaking at 610 nm ((5)D(0)-(7)F(2)) upon 246 nm UV light excitation. No apparent cytotoxicity is observed. Subsequently, time-resolved emission spectroscopy and SQUID magnetometry measurements demonstrate a photoluminescence decay time in milliseconds and paramagnetic behavior, which assure applications of the nanophosphors in biomedical studies.
National Physical Laboratory (CSIR), Dr K S Krishnan Road, New Delhi 110012, India. bipinbhu@yahoo.com
Bipin Kumar
BK
Gupta
Tharangattu N
TN
Narayanan
Sajna Antony
SA
Vithayathil
Yean
Y
Lee
Shyny
S
Koshy
Arava Leela Mohana
AL
Reddy
Avishek
A
Saha
V
V
Shanker
V N
VN
Singh
Benny Abraham
BA
Kaipparettu
Angel A
AA
Martí
Pulickel M
PM
Ajayan
D001943:Breast Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D005063:Europium / Q000737:chemistry*; D006801:Humans; D049408:Luminescent Agents / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D061848:Optical Imaging; D014961:X-Ray Diffraction; D015019:Yttrium / Q000737:chemistry*
D049408:Luminescent Agents; D005063:Europium; D015019:Yttrium; C091417:yttria