Macromolecular Systems with MSA-Capped CdTe and CdTe/ZnS Core/Shell Quantum Dots as Superselective and Ultrasensitive Optical Sensors for Picric Acid Explosive

Abstract

This work reports the development of highly fluorescent materials for the selective and efficient detection of picric acid explosive in the nanomolar range by fluorescence quenching phenomenon. Poly(vinyl alcohol) grafted polyaniline (PPA) and its nanocomposites with 2-mercaptosuccinic acid (MSA)-capped CdTe quantum dots (PPA-Q) and with MSA-capped CdTe/ZnS core/shell quantum dots (PPA-CSQ) are synthesized in a single step free radical polymerization reaction. The thermal stability and photo stability of the polymer increases in the order of PPA < PPA-Q < PPA-CSQ. The polymers show remarkably high selectivity and efficient sensitivity toward picric acid, and the quenching efficiency for PPA-CSQ reaches up to 99%. The detection limits of PPA, PPA-Q, and PPA-CSQ for picric acid are found to be 23, 1.6, and 0.65 nM, respectively, which are remarkably low. The mechanism operating in the quenching phenomenon is proposed to be a combination of a strong inner filter effect and ground state electrostatic interaction between the polymers and picric acid. A portable and cost-effective electronic device for the visual detection of picric acid by the sensory system is successfully fabricated. The device is further employed for quantitative detection of picric acid in real water samples.

Multiple Emitting Amphiphilic Conjugated Polythiophenes‐Coated CdTe QDs for Picogram Detection of Trinitrophenol Explosive and Application Using Chitosan Film and Paper‐Based Sensor Coupled with Smartphone

“…The NH, OH, and CO bonds were observed at 1570, 3450, and 1737 cm −1 , which are then notably shifted to 1520, 3370, and 1717 cm −1 , respectively, after interaction with TNP. [32] This remarkable variation in ζ values of the sensors confirms the electrostatic interaction between the sensors and TNP. [31] The electrostatic interaction was also confirmed by obtaining the variation presented in Figure 5C.…”

Electrospun fluorescent nanofibrous membranes for trace explosive detection

“…2005年美国 佛罗里达州立大学Mattoussi课题组 [100] 首先将量子点 引入爆炸物检测领域, 开发了基于CdSe-ZnS量子点的 爆炸物传感器, 用于TNT的痕量检测, 检出限为 20 ng/mL. 此后, 为了提高检测的特异性和灵敏度, 研 究人员一般利用表面修饰和离子掺杂的量子点检测痕 量爆炸物 [9,101,102] , 但溶液中的量子点容易团聚沉淀, 稳 定性差, 难以器件化, 不便于使用.…”

Triarylamine‐Cored Dendritic Molecular Gel for Efficient Colorometric, Fluorometric, and Impedometeric Detection of Picric Acid

“…Thus, it is very important to effectively monitor and detect PA for social and environmental safety. Recently, different substrates were developed in this regard, such as metal–organic frameworks, polymers, nanomaterials, quantum dots, and carbon dots, though the use of supramolecular gels or self‐assembled materials is still very limited …”