交替共聚物纳米花的自组装及在单颗粒表面增强拉曼散射检测中的应用  

Self-assembly of Alternating Copolymer Nanoflowers and Their Application in Single-particle Surface-enhanced Raman Scattering Detection

作　　者：张常旭 潘辉 周永丰[1] Chang-xu Zhang;Hui Pan;Yong-feng Zhou(School of Chemistry and Chemical Engineering,Shanghai Jiao Tong University,Shanghai 200240)

机构地区：[1]上海交通大学化学化工学院,上海200240

出　　处：《高分子学报》2023年第5期687-696,共10页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号22231007);上海交通大学基础研究试点项目(项目号21TQ1400210)资助.

摘　　要：纳米花(NFs)具有多级的结构,表现出各种各样的功能和应用,因此受到了广泛的关注.然而,大多数的纳米花都是通过无机化合物合成的,关于有机聚合物纳米花的报道非常有限.本文报道了一种结晶性的交替共聚物P(DHB-a-DDT),它可以通过溶液自组装来大量制备聚合物纳米花.纳米花的尺寸可以通过控制聚合物浓度的方法调控,其调控范围为3.3~12.6μm.进一步地,通过聚合物上的硫与银离子的配位然后原位还原,可以制备负载Ag颗粒的纳米花(AgNP-NFs).虽然AgNP-NFs中的Ag含量只有11.9 wt%,但是AgNP-NFs表现出优异的表面增强拉曼散射(SERS)性能,其检测限为1×10^(−8) mo/L,这比从AgNP-NFs上剥离的Ag颗粒低了2个数量级.同时,AgNP-NFs可用于单颗粒SERS检测,这极大地降低了检测成本.这些发现扩展了交替共聚物的自组装行为,丰富了聚合物纳米花的类型和功能.Nanoflowers(NFs)have received much attention due to their hierarchical structures and diverse functions or applications.However,up to now,most reported NFs are synthesized based on inorganic compounds,and the reports on organic polymeric NFs are greatly limited.Here,a crystalline alternating copolymer P(DHB-a-DDT)is synthesized by the click polymerization of 1,3-butadiene diepoxide(BDE)and 1,10-decanedithiol(DDT).It is found that P(DHB-a-DDT)could self-assemble into NFs on a large scale by cooling in a mixed solvent(DMF/MeCN=1/1,V/V)from 80℃to room temperature.The formation mechanism demonstrated that NFs are porous and composed of nanosheets.The size of NFs could be tuned from 3.3μm to 12.6μm by changing the polymer concentration.The self-assembled NFs can be controlled by the factors of polymer concentration,the volume ratio of DMF/MeCN,type of precipitant and polymer composition.Further,the functionalization of NFs is easy to carry out.For example,NFs loaded with Ag particles(AgNP-NFs)are prepared readily by the coordination of sulfur and silver ions followed with in situ reduction.The SEM image show that AgNP-NFs maintained the flower-like morphology,and there are many small Ag nanoparticles(AgNPs)on the surface and in the cavity of AgNP-NFs with the average diameter of(88.4±34.5)nm.As a result,AgNP-NFs with low Ag content of 11.9 wt%exhibit enhanced surface-enhanced Raman scattering(SERS)with a detection limit of 1×10^(−8) mol/L using R6G as the probe molecule,which is two orders of magnitude lower than that of exfoliated AgNPs.Furthermore,AgNP-NFs can be used in single-particle SERS detection with high sensitivity and low detection cost because of their micron size,good dispersibility and porous structure.These findings extend the self-assembled behavior of alternating copolymers(ACPs)and enrich the types of polymeric NFs as well as their functions.

关 键 词：纳米花 交替共聚物 自组装 表面增强拉曼散射 

分 类 号：O641.3[理学—物理化学] O657.37[理学—化学]