地磁环境下基于SQUID三轴磁强计的矢量稳场

超导量子干涉器件(Superconducting Quantum Interference Device, 简称 SQUID) 是一种高灵敏度的矢量磁探测器. 本文采用低温超导SQUID 作为传感器, 搭建了一套三轴矢量磁场稳定装置. 该系统由两个三轴 SQUID磁强计模块、 比例积分微分(PID) 控制器和反馈线圈组组成. 在该系统的矢量稳场下, 磁场波动峰峰值在有效带宽内可以降低四个数量级, 可达pT 量级, 稳场效果显著. 此技术可以满足大部分需要稳定磁场, 如高灵敏度磁传感器的标定等应用场合.     

Fast and Selective Luminescent Sensing by Langmuir–Schaeffer Films Based on Controlled Assembly of Perylene Bisimide Modified with A Cyclometalated AuIII Complex

Condensed films of functional luminophores dominated by the magnitude and dimensionality of the intermolecular interactions play important roles in sensing performance. However, controlling the molecular assembly and regulating photophysical properties remain challenging. In this study, a new luminophore, ortho-PBI-Au, was synthesized by anchoring a cyclometalated alkynyl-gold(III) unit at the ortho-position of perylene bisimide. An unprecedented T-type packing model driven by weak Au-π interaction and Au−H bonds was observed, laying foundation for striking properties of the luminophore. Controlled assembly of ortho-PBI-Au at the air-water interface, realized using the classical Langmuir–Schaeffer technique, afforded the obtained luminescent films with different packing structures. With an optimized film, sensitive, selective, and rapid detection of a hazardous new psychoactive substance, phenylethylamine (PEA), was achieved. The detection limit, response time, and recovery time were <4 ppb, <1 s, and <5 s, respectively, surpassing the performance of the PEA sensors known thus far. The relationship between the characters of films and the sensing performance was systematically examined by grey relational analysis (GRA). The present study suggests that designing novel molecular aggregation with definite adlayer structure is a crucial strategy to enhance the sensing performance, which could be favorable for the film-based fluorescent sensors.