In Vivo Near‐Infrared Imaging Using Ternary Selenide Semiconductor Nanoparticles with an Uncommon Crystal Structure

Abstract

The implementation of in vivo fluorescence imaging as a reliable diagnostic imaging modality at the clinical level is still far from reality. Plenty of work remains ahead to provide medical practitioners with solid proof of the potential advantages of this imaging technique. To do so, one of the key objectives is to better the optical performance of dedicated contrast agents, thus improving the resolution and penetration depth achievable. This direction is followed here and the use of a novel AgInSe2 nanoparticle‐based contrast agent (nanocapsule) is reported for fluorescence imaging. The use of an Ag2Se seeds‐mediated synthesis method allows stabilizing an uncommon orthorhombic crystal structure, which endows the material with emission in the second biological window (1000–1400 nm), where deeper penetration in tissues is achieved. The nanocapsules, obtained via phospholipid‐assisted encapsulation of the AgInSe2 nanoparticles, comply with the mandatory requisites for an imaging contrast agent—colloidal stability and negligible toxicity—and show superior brightness compared with widely used Ag2S nanoparticles. Imaging experiments point to the great potential of the novel AgInSe2‐based nanocapsules for high‐resolution, whole‐body in vivo imaging. Their extended permanence time within blood vessels make them especially suitable for prolonged imaging of the cardiovascular system.

Semiconductor Nanocrystals Emitting in the Second Near‐Infrared Window: Optical Properties and Application in Biomedical Imaging

“…[180,181] Marin and co-workers used AgInSe 2 SNCs with a PL peak at ≈1100 nm for high-resolution whole-body in vivo imaging, where the extended residence time within blood vessels favored prolonged imaging window for the cardiovascular system. [182] For specific imaging applications, appropriate surface functionalization of SNCs is often vital. [63,156] By using InAs-based core/shell SNCs with NIR-II emission, Bawendi and co-workers have designed three imaging platforms, allowing for assessing metabolic, physiologic, and pathologic processes (Figure 5).…”

“…[ 180,181 ] Marin and co‐workers used AgInSe 2 SNCs with a PL peak at ≈1100 nm for high‐resolution whole‐body in vivo imaging, where the extended residence time within blood vessels favored prolonged imaging window for the cardiovascular system. [ 182 ]…”

Recent Advances in Metal Chalcogenide Quantum Dots: From Material Design to Biomedical Applications

“…In the indirect surface encapsulation strategies, MCQDs are encapsulated by amphiphilic molecules [ 120,121 ] or silica shells, [ 122,123 ] overcoming the low colloidal stability and PL QY reduction caused by direct ligand exchange. He et al.…”

Template-Based Controlled Synthesis and Bioapplication of AgInSe2:Zn2+ Near-Infrared Luminescent Quantum Dots※

“…值得注意的是, 在 365 nm 激发下, 对应的发射 峰位置表现出轻微的红移(图 3e), 但是发光强度却呈现 先增加后减小的变化趋势. 在 Ag/In 投料物质的量比为 0.9 时, AgInSe 2 :Zn 2＋ 的发光强度最大, 相较于离子交换 前的 In 2 Se 3 :Zn 2＋ 体系, 强度提高了近 5 倍, PLQY 也从 15.1%提升至 42.5%(见支持信息, 图 S7), 这一数值要远 高于已报道的通过直接法合成的 AgInSe 2 量子点(PLQY 小于 20%) [31][32][33] .…”