NIR luminescent nanomaterials for biomedical imaging

Abstract

Luminescent labels have been widely used for biological applications, primarily in bioimaging and assays. Recently much attention has been focused on the development of luminescent nanoprobes with excitation/emission maxima falling in the region of minimal tissue absorbance/autofluorescence between 650 and 1450 nm, an "imaging window". Tissues have minimal absorbance in this wavelength range allowing for deep penetration of light. This enables whole animal imaging with high sensitivity in core organs in real time without the need for dissection. While several excellent reviews cover various aspects of imaging, there has not been a review that covers NIR imaging nanomaterials adequately. In the present review, we will focus on nanomaterials which can be excited or emitted in NIR I (650-900 nm) and NIR II (1000-1450 nm) regions, including lanthanide based nanoparticles, carbon based nanoparticles, quantum dots and noble metal nanomaterials. We systematically summarize the recent progress in their fabrication and application in biomedical imaging, and discuss the shortcomings, challenges and opportunities in it.

Upconversion improvement by the reduction of Na+-vacancies in Mn2+ doped hexagonal NaYbF4:Er3+ nanoparticles

“…2d). The size-shrinkage effect of NaYbF 4 UCNPs induced by doping Mn 2+ is similar to the previous report of NaYF 4 :Mn 2+ /Er 3+ UCNPs (Fig. Fig.…”

“…2a. An additional high-resolution TEM image of NaYbF 4 Undoubtedly, EDX is a convenient way to reveal a change in the elemental composition of crystals. The doping of 10 mol% Mn 2+ slightly reduces the diameter of UCNCs to 80 nm (Fig.…”

“…[1][2][3][4] These unique properties, coupled with size-and shape-independent luminescence phenomena, confer Ln 3+ doped nanoparticles (NPs) applications in a very wide range of fields. [1][2][3][4] These unique properties, coupled with size-and shape-independent luminescence phenomena, confer Ln 3+ doped nanoparticles (NPs) applications in a very wide range of fields.…”

In vivo targeted magnetic resonance imaging and visualized photodynamic therapy in deep-tissue cancers using folic acid-functionalized superparamagnetic-upconversion nanocomposites

“…At present, the clinical use of PDT was restricted due to the 40 weak penetration in deep tissues and the non-specific damage to normal tissues. It was known that visible/ultraviolet (UV) lights (about 400-700 nm) had weak penetration by only a few millimeters, but near-infrared (NIR) lights (about 700-1100 nm) had deep one in tissues by one to several centimeters [15][16][17][18]. The 45 targeting strategy of nanoprobes was critical to improve their selectivity in imaging and therapy of cancers, which would reduce the non-specific damage [19].…”

Over-1000 nm Near-infrared Fluorescence and SPECT/CT Dual-modal <i>in vivo</i> Imaging Based on Rare-earth Doped Ceramic Nanophosphors

“…RED-CNPs are known to show strong OTN-NIR emission under NIR excitation [7,8]. Since then, other groups have reported the in vivo OTN-NIR fluorescence imaging by using RED-CNPs [9][10][11][12][13][14].…”