Key Lab for Special Functional Materials, Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, and Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China.
Inorg Chem. 2021 May 3;60(9):6503-6513. doi: 10.1021/acs.inorgchem.1c00304. Epub 2021 Apr 13.
Low-toxic InP quantum dots (QDs) as an ideal candidate for Cd-based QDs have tremendous potential for next-generation commercial display and biological detection applications. However, the progress in biological detection is still far behind that of the Cd-based QDs. This is mainly because the InP-based QDs are of inferior stability and photoluminescence quantum yield (PL QY) in aqueous solution. Here, PL QY of 65% and excellent stability of InP/GaP/ZnS QD@SiO nanoparticles have been successfully synthesized a silica coating method. The containing thiol-capped hydrophobic InP/GaP/ZnS QDs were pre-silanized with waterless, ammonia-free hydrolysis tetraethyl orthosilicate, and subsequently, an outer silica shell was generated in the reverse microemulsion. The corresponding QD-based fluorescence-linked immunosorbent assay exhibits a high sensitivity of 0.9 ng mL for C-reactive protein and the broad detection range of 1-1000 ng mL, which was close to that of the state-of-the-art Cd-based QD@SiO nanoparticles and had the highest sensitivity of Cd-free QDs so far. This work provides a very successful silica coating method for the containing thiol-capped hydrophobic QDs and the QDs highly sensitive to water and oxygen, and the obtained InP/GaP/ZnS QD@SiO nanoparticles were considered as the robust, biocompatible, and promising Cd-free fluorescent labels for the further ultra-sensitive detection.
低毒的 InP 量子点（QDs）作为 Cd 基 QDs 的理想候选物，在下一代商业显示和生物检测应用方面具有巨大的潜力。然而，生物检测方面的进展仍然远远落后于 Cd 基 QDs。这主要是因为 InP 基 QDs 在水溶液中的稳定性和光致发光量子产率（PL QY）较差。在这里，通过一种硅涂层方法成功合成了具有 65%的 PL QY 和优异稳定性的 InP/GaP/ZnS QD@SiO 纳米粒子。首先，对含有巯基封端的疏水性 InP/GaP/ZnS QDs 进行无水无氨水解四乙氧基硅烷预硅烷化，然后在反相微乳液中生成外硅壳。基于 QD 的荧光免疫分析显示出对 C 反应蛋白的高灵敏度为 0.9ng/mL，检测范围为 1-1000ng/mL，与最先进的 Cd 基 QD@SiO 纳米粒子非常接近，并且是迄今为止无镉 QDs 中灵敏度最高的。这项工作为含有巯基封端的疏水性 QDs 和对水和氧气高度敏感的 QDs 提供了一种非常成功的硅涂层方法，所获得的 InP/GaP/ZnS QD@SiO 纳米粒子被认为是用于进一步超灵敏检测的稳健、生物相容且有前途的无镉荧光标记物。
