基于施主-受主缺陷对调控策略的高亮度近红外IIa 区发光CuInSe2量子点的构建及荧光成像应用

近红外IIa（1000nm-1400nm)区光学窗口能够有效克服活体成像面临的自荧光、血液及组织吸收、光散射等生物学干扰，是高质量成像新窗口。高亮度（高荧光量子产率）近红外IIa区荧光体开发是生物医学应用的关键。计量学CuInSe2低毒且禁带宽度极低（1.04 eV）是理想的近红外IIa发光体。然而受困于量子限域效应，理论上很难通过尺寸改变在近红外IIa区发光同时获得高量子产率。本申请拟基于缺陷对发光机制，通过引入施主-受主缺陷对进行CuInSe2量子点光学改性，兼顾近红外IIa区发光调制与亮度提高。利用对发光机制的深入研究与发光效率的定量解析，建立量子限域效应下施主-受主缺陷对光学性能调控的理论模型与技术路线，并基于活体生理机能动态监测及深层病变组织的成像示踪应用，开发两类表面生物功能化探针开展应用性评价。

For in vivo imaging, near infrared IIa region (1000–1400 nm) provides several advantages: general lack of autofluorescence, low light absorption by blood and tissue, and reduced scattering. The development of fluorescent labels with high brightness (high quantum yield) in IIa region plays an important role in biomedical research community. Stoichiometric CuInSe2 with low toxicity and narrow band gap of 1.04 eV is an ideal NIR IIa emitter. In consideration of quantum confinement effect, it is unable to achieve high quantum yield in NIR IIa through size change. In present proposal, defects-related light emitting mechanism is exploited to realize high quantum yield in NIR IIa by introduction of donor-acceptor pair in stoichiometric CuInSe2 quantum dots. The theoretical model and technical route of optical properties control with consideration of quantum confinement effect is built with help of intensive study of emitting mechanism and quantitative analysis of light emitting efficiency. To demonstrate the imaging capabilities of high brightness NIR IIa CuInSe2 quantum dots, two kinds of biocompatible functionalized probes for physiology and deep pathological tissue imaging applications are developed and evaluated in vivo.