大气环境中NOx/SO2的上转换发光编码分析方法

Because of the serious harm to human health, smog has been attracted more and more attentions in recent years. Nitrogen oxides (NOx) and sulfur dioxide (SO2) are the major components of smog. However, due to the low concentrations in atmosphere and easy to be photo-oxidized, current detection methods suffer from many disadvantages, such as poor sensitivity, easy to be interfered by environment factors, costly and cumbersome, not suitable for rapid and real-time detection, and so on. In this project, we will explore upconversion luminescence encoding technology coupled with smartphone-based detection system to realize rapid detection of NOx and SO2 in atmosphere. 1) We will design and synthesis of multi-color encoded upconversion luminescent nanoparticles (UCNPs), which would effectively improve detection sensitivity through reducing the background signals of complex atmosphere sample by the use of NIR excitation of UCNPs. 2) To obtain high selectivity towards NOx and SO2, we will couple upconversion nanoparticles with specific organic ligands, and then develop a multi-signal output and analysis method to achieve the simultaneous detection of NOx and SO2. 3) By the employment of 3D printing technology, we will fabricate an accessory of smartphone, to construct a portable and low-power upconversion luminescence detection system for quantitative testing of atmosphere sample. The expected results of this project will provide scientific basis and technical guidance for the fast and real-time monitoring hazardous gases in atmosphere, and will be of extensive social and economic significance for effectively control of the pollutants discharge.

氮氧化物（NOx）和二氧化硫（SO2）是构成雾霾的主要气体污染物，现有的检测方法存在易受环境温度湿度等因素干扰，灵敏度低，不能实现多组分气体的同步检测等缺点。本项目拟发展上转换发光编码分析方法，构建基于智能手机平台的即时检测系统，实现大气环境中NOx和SO2的同步快速检测。具体地：1）设计并合成具有蓝光、绿光和红光（RGB）多种颜色编码的上转换发光纳米颗粒，利用其近红外光激发的特点，有效地降低大气样品的背景信号，提高检测灵敏度；2）在纳米颗粒表面进行NOx和SO2特异性有机功能配体修饰，通过上转换发光编码多重信号的解析实现NOx和SO2的选择性识别；3）利用3D打印等微加工技术进一步开发基于智能手机平台、便携低功耗的上转换发光检测系统，实现大气污染物的同步快速定量检测。项目预期成果为大气环境的实时监控提供新的技术基础，对有效控制污染物的排放具有十分重要的社会、经济价值。

氮氧化物（NOx）和二氧化硫（SO2）是构成雾霾的主要气体污染物，现有的检测方法存在易受环境因素干扰，灵敏度低，不能实现多组分气体的同步检测等缺点。本项目利用镧系稀土离子丰富的能级结构，通过交叉弛豫和距离调节能量转移等机制，成功设计并合成了具有绿光和红光编码的上转换发光纳米颗粒，并在颗粒表面修饰罗丹明衍生物、花菁染料等特异性有机功能配体，构建NOx和SO2上转换发光探针。利用3D打印等微加工技术开发基于智能手机的便携低功耗上转换发光检测系统，识别上转换纳米探针构筑的试纸上发光信号变化，实现NOx和SO2气体的快速识别，该方法对NO的检出限达到2 ppb，对SO2检出限达到0.78 ppb，均满足大气环境检测的需要。此外，在本项目的资助下，我们利用上转换发光材料低背景信号干扰、单一激发多种发射等优势，也积极探索了一些上转换发光纳米探针在光基因表达方面的应用。利用Er离子掺杂的正交发光纳米材料构建光遗传学探针，实现了心肌细胞膜上两种光基因蛋白VChR1和Jaws的程序化激活，从而达到可逆控制心肌细胞跳动快慢的目的，相关成果发表后，Nature杂志以highlight形式报道了我们的工作。上述研究工作在《Nature Commun.》，《Adv. Mater.》，《Adv. Sci.》，《Anal. Chem.》，《ACS Sensors》，《Analyst》，《中国光学》等期刊以第一/通讯作者发表相关论文8篇，获授权中国发明专利两项。