基于碲化镉量子点的比率荧光传感体系对茶油中Hg2+的可视化半定量检测

一种简单的比率荧光体系被设计用于茶油中Hg2+含量的快速、灵敏、可视化检测。该体系由具有红色荧光的碲化镉量子点（Cd/Te QDs）与自身呈蓝色荧光的茶油组成，可以对茶油中的Hg2+进行检测分析，其检出限低至6.04 nM。调节合适的荧光强度比使传感体系的荧光发射呈粉红色，加入Hg2+后由于电荷转移作用使体系中CdTe QDs的红色荧光被淬灭，随着Hg2+浓度的增加，体系发生从粉色到蓝色的显著颜色演变。为了评价比率荧光体系检测Hg2+的选择性，在相同条件下对比率荧光体系加入不同金属离子，体系的荧光强度和颜色没有变化。进一步添加200 nM的Hg2+后，体系的荧光强度比（I677/I431）大大降低，颜色发生明显变化，说明此体系具有较强的抗干扰能力，满足实际样品的检测需求。这种简便的检测手段快速、灵敏，成本低，为茶油中重金属离子的快速可视化检测提供了新的策略。

Visual Semi-quantitative Detection of Hg2+ in Camellia Oil Using a Cadmium Telluride Quantum Dot-based Ratiometric Fluorescence Sensing System

A simple ratiometric fluorescence system was designed for rapid, sensitive and visual detection of the Hg2+ content in camellia oil. The system was composed of cadmium telluride quantum dots (Cd/Te QDs) with red fluorescence and camellia oil naturally with blue fluorescence, and can detect and analyze the Hg2+ content in camellia oil (as low as 6.04 nM). Appropriate adjustment of fluorescence intensity ratio made the fluorescence of the sensor system turn pink. The red fluorescence of CdTe QDs in the system was quenched due to the charge transfer upon the addition of Hg2+. With the increase of the Hg2+ concentration, the color of the system exhibited significant color change (from pink color to blue color). In order to evaluate the selectivity of the ratio fluorescence system towards Hg2+, different metal ions were added to the ratiometric fluorescence system under the same conditions did not change the fluorescence intensity and color of the system. Further addition of 200 nM of Hg2+ decreased greatly the fluorescence intensity ratio (I677/I431) of the system and changed significantly the fluorescence color. These results indicated that thus this system exhibited strong anti-interference ability and could meet the detection requirements of actual samples. The simple method is fast, sensitive and inexpensive, and provides a new strategy for rapid detection of heavy metal ions in camellia oil.