碳点嫁接海藻酸钙复合结构的制备及其对Cu2+的检测

基于铜离子与碳点的荧光猝灭作用，建立了用碳点作为荧光探针来检测铜离子的新方法。该方法将碳点还原后再嫁接于海藻酸钙，从而得到一种新型的含还原碳点的海藻酸钙薄膜荧光探针。用荧光分光光度计和紫外-可见分光光度计对探针的荧光特性以及探针与金属离子的相互作用进行了研究。研究结果表明：改性后的荧光探针具有很高的荧光强度，因此可以根据探针荧光强度的变化实现对铜离子的检测，并通过乙二胺四乙酸二钠（EDTA）的作用实现对铜离子的重复检测。铜离子浓度在5×10^-6~100×10^-6 mol·L^-1范围内与该荧光探针的荧光猝灭强度呈良好的线性关系。该方法不仅可以对铜离子检测，更实现了对碳点的固载，该技术有望实现荧光探针的回收再利用。

Preparation of Complex Carbon-dot-grafted Calcium Alginate and Its Application as Fluorescent Sensor for Cu2+

A novel method for detecting Cu²⁺ ion was developed based on the fluorescence quenching effect of copper ion on carbon dots (CDs). The fluorescent probe was prepared by grafting reduced carbon dots (rCDs) in calcium alginate to form a calcium alginate film (CA-rCDs). Fluorescence characteristics of the probe and interaction between the probe and metal ions were studied using fluorescence spectrophotometer and UV-Vis spectrophotometer. The results show that the fluorescence intensity of the novel probe is strong and varied with the concentration of Cu²⁺. Moreover, the quenched fluorescence intensity of probe is linearly proportional to the concentration of Cu²⁺ in the range from 5×10^-6 to 100×10^-6 mol·L^-1. In addition, it is found that the probe can detect Cu²⁺ repeatedly by using EDTA. This method is not only suitable for the detection of Cu²⁺, but also can realize the immobilization of CDs, ensuring the probe to be recycled and reused.