Lifetime-Encoded Infrared-Emitting Nanoparticles for in Vivo Multiplexed Imaging

Abstract

Advanced diagnostic procedures are required to satisfy the continuously increasing demands of modern biomedicine while also addressing the need for cost reduction in public health systems. The development of infrared luminescence-based techniques for in vivo imaging as reliable alternatives to traditional imaging enables applications with simpler and more cost-effective apparatus. To further improve the information provided by in vivo luminescence images, the design and fabrication of enhanced infrared-luminescent contrast agents is required. In this work, we demonstrate how simple dopant engineering can lead to infrared-emitting rare-earth-doped nanoparticles with tunable (0.1-1.5 ms) and medium-independent luminescence lifetimes. The combination of these tunable nanostructures with time-gated infrared imaging and time domain analysis is employed to obtain multiplexed in vivo images that are used for complex biodistribution studies.

High‐Capacity Upconversion Wavelength and Lifetime Binary Encoding for Multiplexed Biodetection

“…In addition, with the development of time‐resolved measurement instruments, differentiating (decoding) the lifetime of UCNPs is now easy to implement. Similar to regulating the emission spectra, the lifetime of UCNPs can also be manipulated through the energy transfer pathway,,, and recent studies revealed that the lifetime for a single emission band can be tuned in a large range from micro‐ to milliseconds by controlling dopant concentration,,,, UCNPs size, and the luminescence resonance energy transfer (LRET) process ,. In the frequency domain, the phase angle is also explored in response to a harmonic‐wave excitation as an encoding dimension, which is determined by both the noticeable rise and decay of lifetime.…”

“…Therefore, the lifetime at 475 nm was effectively extended from 632 μs to 836 μs with incremental thickness of S1 from d =1.5 nm to d =5.4 nm, as shown in Figure E (abbreviated as τ b1 , τ b2 , and τ b3 , respectively). Besides, this structure also allows the luminescence lifetime to be shortened by increasing the activators concentration,, as conventional method to further expand the lifetime space. Significantly, in contrast to other energy transfer ways to manipulate lifetimes,,, which accompanied with huge variation in emission intensities, the intensity of τ b ‐UCNPs can be finely tuned by varying the thickness of S2 to keep almost consistent but with little affection of lifetime (Figure S4), which in turn expands the available lifetime identities.…”

A New Generation of NIR‐II Probes: Lanthanide‐Based Nanocrystals for Bioimaging and Biosensing

“…Despite the large number of achievements obtained in the NIR‐II region, in vivo multiplexed (IVM) imaging is still a big challenge for spectra because of the limited number of fluorescent probes and the complex tissue structures. So far, only a few researchers have reported IVM imaging based on two probes at a time or one probe with different lifetime . However, neither of the work realizes assessment of quantitative accuracy.…”

Lanthanide-doped mesoporous MCM-41 nanoparticles as a novel optical–magnetic multifunctional nanobioprobe

“…With fascinating optical properties like a large Stokes shi, long excited-state lifetimes, photo-chemical stability, and narrow emission bands, trivalent lanthanide ion (Ln 3+ ) doped nanoparticles have attracted signicant attention in biological imaging, [1][2][3][4] biomolecule detection, [5][6][7] security encoding, [8][9][10] and cancer therapeutics. [11][12][13] Many efforts have been made to improve the luminescence performance by optimizing the size, shape, and doping concentration of the Ln 3+ -doped luminescence nanoparticles.…”