溶液环境中CdSeS量子点与金纳米颗粒相互作用

摘要

选用不同发射波长的合金型CdSeS量子点((QDs),研究溶液状态下量子点和金纳米颗粒(AuNPs)相互作用及离子强度、pH值、距离等诸多因素对相互作用的影响,在此基础上对相互作用的机理进行了分析.在溶液状态下,金纳米颗粒可以高效地淬灭量子点.Stern-Volmer淬灭常数K,r值在10～8L·mol-1,数量级.这种淬灭效应与距离、光谱之间叠合程度等密切相关,受溶液极性、离子强度、pH值的影响较小.金纳米颗粒与量子点相互作用的机理较为复杂,以能量转移为主.研究结果对设计更高效的生物传感器及更全面认识金纳米颗粒与量子点相互作用的机理具有重要意义.%We studied the interaction between CdSeS quantum dots (QDs) and gold nanoparticles (AuNPs) in solution.We found that the photoluminescence (PL) intensity of the QDs was efficiently quenched by the AuNPs with extraordinarily high Stern-Volmer quenching constant (Ksv) values that approach 108 L·mol-1.The quenching efficiency is strongly related to the spectral overlap and the distance between the QDs and AuNPs and is independent of solvent polaritym, ion strength, and pH value.These results suggest that this superquenching behavior can be attributed to a long-range (F(o)rster-type) energy transfer.Our findings allow for the design of exquisite multiple F(o)rster resonance energy transfer (FRET)-based biosensors for the highly sensitive and simultaneous monitoring of multiple molecules in live cells.