中文摘要：

本文构建了以上转换纳米粒子（Upconversion Phosphors，UCPs）为供体，氧化碳球为受体的荧光共振能量转移新体系用于Ag＋的检测。氧化碳球对上转换荧光供体的发射具有良好的猝灭效果，当氧化碳球的浓度达到0．038mg／mL时，猝灭效率最大，达到78％。向该体系中加入Ag＋后，在浓度为1～100nmol／L范围内，UCPs的荧光恢复程度与Ag＋的浓度呈线性关系。该方法测定Ag＋的检出限为0．98nmol／L。本实验首次尝试构建以氧化碳球为受体的荧光共振能量转移（FRET）传感器来检测Ag＋，结合了UCPs的上转换发光特性和氧化碳球优良的猝灭能力以及良好的分散性，为Ag＋的检测提供了一个新的方法。

英文摘要：

In this study,we constructed a new aptamer biosensor for the determination of Ag＋ based on fluorescence resonance energy transfer （FRET） from upconversion phosphors （UCPs） to carbon nanoparticles oxide（CNPs oxide）. CNPs oxide was found to be a good energy acceptor for UCPs,with up to 78 % fluorescence quenching degree obtained. The donor fluorescence restoration was linearly related to Ag＋ within the concentration range from 1 nmol/L to 100 nmol/L,and a detection limit of as low as 0.98 nmol/L was acquired in aqueous solution. This is the first report that UCPs and CNPs oxide were employed as a donor-acceptor pair to construct FRET-based biosensors, which utilized both the upconversion photophysical merits of UCPs and the superquenching ability and good water-solubility of CNPs oxide. The proposed UCPs-FRET sensor afforded favorable analytical performances in the detection of Ag＋ ,which also opened the way to a new class of upconversion FRET assays.