基于纳米金Core-satellites等离子体耦合增强效应的汞离子光纤传感器的研究

以DNA杂交双链为联接,构建纳米金颗粒Core-satellites结构并激发等离子体耦合增强效应,利用Hg^(2+)可与DNA中胸腺嘧啶T形成T-Hg^(2+)-T特异性结构,研制了用于检测水中Hg^(2+)的局域等离子体共振(LSPR)光纤传感器。待测溶液中的Hg^(2+)能够引起富含T的DNA单链折叠,抑制DNA杂交反应,降低等离子体耦合强度,改变LSPR谐振波长。通过检测谐振波长红移变化,实现对Hg^(2+)浓度的定量检测。本方法检测Hg^(2+)的线性范围为5~150 nmol/L,检出限为3.4 nmol/L(3σ)。Zn^(2+)、Mg^(2+)、Pb^(2+)等重金属离子对Hg^(2+)检测无明显干扰作用。实际水样中Hg^(2+)加样回收率为94.2%~105.4%,相对标准偏差<4.8%。

Sequentially responsive size reduction and drug release of core-satellite nanoparticles to enhance tumor penetration and effective tumor suppression

Poor tumor accumulation remains a serious challenge for nanomedicines to achieve ideal antitumor outcomes.The different size preferences for systematic circulation,tumor retention and deep permeation have attracted great attention when designing antineoplastic nano-delivery system.Herein,we developed a nano-system which can shrink its size in tumor microenvironment to achieve better tumor retention and penetration.In this work,the cationic bovine serum albumin-protected,doxorubicin-loaded gold nanoclusters(CAuNC-DOX)and amino-functionalized mesoporous silica nanoparticles(MSN)are connected by Fe^(2+)and are further coated with hyaluronic acid(HA)to obtain a core-satellite MSN-Fe-CAuNCDOX@HA nano system(MFADH).When reaching the tumor site,the HA shell,which endows the system with both good biocompatibility and preferable tumor targeting ability,was disintegrated,followed by acid-stimulated release of small-sized pharmacological unit—CAuNC-DOX for further tumor penetration.As demonstrated in both in vitro and in vivo results,MFADH showed excellent antitumor effect,providing a proof of concept for the feasibility of shrinkable nanoplatforms in tumor treatment.

Engineering the inter-island plasmonic coupling in homometallic Au-Au_(n)core-satellite structures

We show that through strong ligand mediated interfacial energy control between Au seeds and the deposited Au,the non-wetting growth of Au on Au seeds led to the formation homometallic core-satellite nanostructures.To modulate the intraparticle plasmonic coupling between the core and the satellites,the number and size of the Au satellites,and their inter-island distances were continuously tuned by varying the growth kinetics.As a result of the precise structural control,the plasmonic absorptions of the core-satellite nanostructures were tuned from visible to near-infrared(NIR)spectral range,and the extent of spectral modulation(500-1300 nm)is among the best of the literature methods.This synthetic advance enriches the toolbox for nanosynthesis and points to a new direction in the exploration of sophisticated functional designs.

Core-satellite metal-organic framework@upconversion nanoparticle superstructures via electrostatic self-assembly for efficient photodynamic theranostics

The nanoplatforms based on upconversion nanoparticles(UCNPs)have shown great promise in amplified photodynamic therapy(PDT)triggered by near-infrared(NIR)light.However,their practical in vivo applications are hindered by the overheating effect of 980 nm excitation and low utilization of upconversion luminescence(UCL)by photosensitizers.To solve these defects,core-satellite metal-organic framework@UCNP superstructures,composed of a single metal-organic framework(MOF)NP as the core and Nd3+-sensitized UCNPs as the satellites,are designed and synthesized via a facile electrostatic self-assembly strategy.The superstructures realize a high co-loading capacity of chlorin e6(Ce6)and rose bengal(RB)benefitted from the highly porous nature of MOF NPs,showing a strong spectral overlap between maximum absorption of photosensitizers and emission of UCNPs.The in vitro and in vivo experiments demonstrate that the dual-photosensitizer superstructures have trimodal(magnetic resonance(MR)/UCL/fluorescence(FL))imaging functions and excellent antitumor effectiveness of PDT at 808 nm NIR light excitation,avoiding the laser irradiation-induced overheating issue.This study provides new insights for the development of highly efficient PDT nanodrugs toward precision theranostics.

Construction of Au@Pt core-satellite nanoparticles based on in-situ reduction of polymeric ionic liquid protected gold nanoparticles

A method of in-situ reduction to prepare Au@Pt core-satellite nanopar- ticles （NPs） is described by using Au NPs coating poly[1-methyl 3-（2-methacryloyloxy propylimidazolium bromine）] （PMMPImB-@-Au NPs） as the template. After electrostatic complex chloroplatinic acid with PMMPImB shell, the composite NP was directly reduced with N2H4 to produce Au@Pt core-satellite NPs. The characterization of composite and core-satellite NPs under different amounts of chloroplatinic acid were studied by DLS, UV-vis absorption spectrum and TEM. The satellite Pt NPs with a small size （-2 nm） dotted around Au core, and the resulting Au@Pt core-satellite NPs showed a red-shift surface plasmon resonance （SPR） and a good dispersion due to effectively electrostatic repulsion providing by the polymeric ionic liquid （PIL） shell. Finally, Au@Pt core-satellite NPs exhibit an enhanced catalytic activity and cycled catalytic capability for the reduction ofp- nitrophenol with NaBH4.