Extended Data Fig. 4: Optimization and characterization of synthesized UCNPs.
From: Nano-optogenetic engineering of CAR T cells for precision immunotherapy with enhanced safety
a, Comparison of the the core/shell structures of synthesized UCNPs (top, β-NaYF4:30% Yb, 0.5% Tm@NaYF4; bottom, β-NaYbF4:0.5%Tm@NaYF4) and TEM images (right). Scale bar, 100 nm. b, TEM images and the size distribution (height denoted as ‘H’ and diameter denoted as ‘D’) of the NaYbF4:0.5%Tm core nanoparticles (left), NaYbF4:0.5%Tm@NaYF4 core-shell nanoplates (middle), and silica-coated NaYbF4:0.5%Tm@NaYF4 core-shell nanoplates (right). c, Comparison of the upconversion luminescence spectra of synthesized UCNPs upon NIR light illumination at 980 nm (black, β-NaYF4:30%Yb,0.5%Tm@NaYF4; red, β-NaYbF4:0.5%Tm@NaYF4 nanoplates). Their luminescence intensities were compared at the same condition with the same amounts of total lanthanide ions. d, Blue light emitting from the leftmost cuvette containing UCNPs (β-NaYbF4:0.5%Tm@NaYF4) upon NIR illumination. The UCNP-containing cuvette (leftmost) was placed next to the indicated numbers of H2O-containing plastic cuvettes (labeled as 1, 2 and 3; top) or a cuvette containing dark ink (bottom). The NIR light source (980 nm) was placed on the right. Pictures were taken in a dark room except for the leftmost images. The light intensity was strong enough to illuminate the background after penetrating through cuvettes. e, UCNPs emitted bright blue light locally at the injection site in vivo upon NIR light stimulation (980 nm; 250 mW/cm2). Pictures were taken for the same mouse in the bright field without (left) or with NIR light (middle), or in the dark field with NIR light (right).
