摘要
AgInSe_(2)(AISe)量子点具有带隙小、斯托克斯位移大、荧光寿命长且不含重金属有毒元素等特性,使其在生物医学领域具有重要研究价值.同时,AISe量子点的光学性质对尺寸和组成具有强烈的依赖关系,然而传统的直接合成法很难实现对AISe量子点形貌和组分的精准调控,从而极大限制了其发光效率.对此,作者提出了温和条件(75℃)下以In_(2)Se_(3):Zn^(2+)量子点为模板,离子交换法控制合成AISe近红外荧光量子点的策略,所合成的AISe量子点很好地维持了In_(2)Se_(3):Zn^(2+)模板的形貌,进一步通过系统调节Ag/In投料物质的量比控制离子交换程度,AISe量子点的实际Ag/In组分比实现了从0.26~1.09宽范围调节;最高绝对量子产率可达42.5%,这一数值远高于通过直接合成法所得到的AISe量子点.通过稳态、瞬态和低温光谱等手段对不同组分AISe量子点的发光行为进行了系统的光谱学研究,揭示了其发光机理.另外,利用AISe量子点高效的近红外发光和良好的生物安全性,实现了基于AISe近红外量子点探针的肿瘤细胞靶向成像,展示出AISe量子点在生物成像和疾病的早期诊疗等领域具有很好的应用潜力.
AgInSe_(2)(AISe)quantum dots(QDs)exhibit large Stokes shift,composition-dependent photoluminescence(PL),long PL lifetimes and low toxicity,making them exceptional candidates in a wide variety of bioapplications.However,it remains notoriously challenging to precisely control both the morphology and composition to optimize the PL performance of AISe QDs via conventional direct synthesis.Herein,we develop the unique low-temperature(75℃)template-based synthesis of highly efficient near-infrared(NIR)luminescent AISe QDs from In_(2)Se_(3)QDs via a facile cation exchange method.The brief synthesis AISe QDs process was as follows:firstly,indium acetate was dissolved in non-coordinating solvent octadecene.Selenium precursor was injected into the above mixture at 200℃,followed by nucleation and growth within a few minutes.Thereafter,In_(2)Se_(3)template QDs can be acquired,and the dispersity of the as-prepared QDs can be improved by adding zinc.Secondly,silver acetate was added to the In_(2)Se_(3):Zn^(2+)QDs solution with stirring for 15 min at 75℃.Finally,AgInSe_(2):Zn^(2+)QDs were obtained.The proposed method enables the as-prepared AISe QDs to inherit the size and morphology of the template QDs.The extent of cation exchange can be controlled by rationally manipulating the Ag/In precursor molar ratio.We successfully regulate the stoichiometry of Ag/In ratio from 0.26 to 1.09.As a result,highly efficient luminescence of AISe QDs with the maximum absolute quantum yield of 42.5%has been achieved,which is higher than that of the AISe counterparts synthesized via the direct method.Moreover,we survey the luminescence mechanism of AISe QDs by means of the steady-state,transient and temperature-dependent spectroscopies.AISe nanoprobes were prepared by coating the hydrophobic QDs with a layer of 1,2-distearoyl-sn-glycero-3-phosphoethanol-amine-N-[biotin(polyethyleneglycol)-2000](DSPE-PEG-Biotin)phospholipids through hydrophobic interaction.By virtue of the excellent biocompatibility and intense NIR emission,we exemplify the
作者
廉纬
方泽铠
涂大涛
李嘉尧
韩思远
李仁富
商晓颖
陈学元
Lian Wei;Fang Zekai;Tu Datao;Li Jiayao;Han Siyuan;Li Renfu;Shang Xiaoying;Chen Xueyuan(College of Chemistry,Fuzhou University,Fuzhou 350108,China;CAS Key Laboratory of Design and Assembly of Functional Nanostructures,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,China;State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,China)
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2022年第5期625-632,1-19,共27页
Acta Chimica Sinica
基金
国家自然科学基金(Nos.U1805252,21975257,22135008)
福建省自然科学基金(Nos.2019I0029,2021L3024)资助
