Preparation of Highly Stable and Photoluminescent Cadmium-Free InP/GaP/ZnS Core/Shell Quantum Dots and Application to Quantitative Immunoassay
Preparation of Highly Stable and Photoluminescent Cadmium-Free InP/GaP/ZnS Core/Shell Quantum Dots and Application to Quantitative Immunoassay
复制标题
高稳定光致发光无镉InP/GaP/ZnS核/壳量子点的制备及其在定量免疫分析中的应用
DOI：
10.1002/ppsc.201900441
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发表时间：
2020
影响因子：
2.7
通讯作者：
Li Lin Song
中科院分区：
文献类型：
--
作者：
Xu Yanxia;Lv Yanbing;Wu Ruili;Shen Huaibin;Yang Huawei;Zhang Han;Li Jinjie;Li Lin Song
磷化铟（InP）量子点（QDs）是目前广泛应用的镉基量子点的理想替代品，具有良好的环保性能和对人体的安全性，在生物领域具有广阔的应用前景。然而，合成具有生物相容性、高量子产率、均匀粒径和高稳定性的InP核壳量子点仍然是一个具有挑战性的课题。本文以GaP为中间层，1 -辛烷硫醇为新的S源，通过多次注入壳前驱体和延长壳生长时间，合成了高质量（QY高达72%）厚壳InP/GaP/ZnS核/壳量子点（12.8±1.4 nm）。厚壳InP/GaP/ZnS核/壳量子点在转移到水中后仍保持较高的量子量和光稳定性。以InP/GaP/ZnS核/壳QDs为荧光标记，建立基于QD的荧光连锁免疫吸附法（QD‐FLISA）定量检测C反应蛋白（CRP），并建立荧光强度与CRP浓度之间的校准曲线（范围：1 ~ 800 ng mL−1，相关系数：R2= 0.9992）。检测限为2.9 ng mL−1，与先前报道的无镉QD免疫测定相比增加了两倍。因此，InP/GaP/ZnS核壳量子点作为一种很有前途的荧光标记材料，为生物医学领域的无镉敏感和特异性免疫检测提供了一条新的途径。
Indium phosphide (InP) quantum dots (QDs) are ideal substitutes for widely used cadmium‐based QDs and have great application prospects in biological fields due to their environmentally benign properties and human safety. However, the synthesis of InP core/shell QDs with biocompatibility, high quantum yield (QY), uniform particle size, and high stability is still a challenging subject. Herein, high quality (QY up to 72%) thick shell InP/GaP/ZnS core/shell QDs (12.8 ± 1.4 nm) are synthesized using multiple injections of shell precursor and extension of shell growth time, with GaP serving as the intermediate layer and 1‐octanethiol acting as the new S source. The thick shell InP/GaP/ZnS core/shell QDs still keep high QY and photostability after transfer into water. InP/GaP/ZnS core/shell QDs as fluorescence labels to establish QD‐based fluorescence‐linked immunosorbent assay (QD‐FLISA) for quantitative detection of C‐reactive protein (CRP), and a calibration curve is established between fluorescence intensity and CRP concentrations (range: 1–800 ng mL−1, correlation coefficient:R2= 0.9992). The limit of detection is 2.9 ng mL−1, which increases twofold compared to previously reported cadmium‐free QD‐based immunoassays. Thus, InP/GaP/ZnS core/shell QDs as a great promise fluorescence labeling material, provide a new route for cadmium‐free sensitive and specific immunoassays in biomedical fields.