A single cataluminescence sensor based on spectral array and its use in the identification of vinegars

Instant Fingerprint Discrimination for Military Explosive Vapors by Dy3+ Doping a La2O3-Based Cataluminescence Sensor System

With the intensification of explosive-based terrorism attack and environmental concerns, the innovation of high-efficiency and portable sensors for facile, rapid, and reliable monitoring of explosives has become one of the major demands in societies. Herein, a reliable and easy-to-use cataluminescence sensor system based on Dy³⁺ doping La₂O₃ nanorod catalysts has been developed for the identification and detection of six types of military explosive vapors, including homologous compounds and even isomers. The efficient discrimination is to make full use of the thermodynamic and kinetic information that can be extracted from the catalytic oxidation process of explosive molecules on various sensing materials, that is, the response signal and response time to generate the fingerprint of each target compound, while the rapid detection of the strategy can be manifested in response toward six military explosive vapors within 2.5 s and recover within 4 s. Meanwhile, the quantitative analysis of the explosives by the sensor system was realized based on 0.8%Dy:La₂O₃ with optimal catalytic activity, and the detection limits of NB, m-MNT, m-DNB, PNT, DNT, and TNT can reach 0.62, 0.49, 0.63, 0.38, 0.023, and 0.067 μg mL^-1. In this research, we also constructed a novel sensor device and detection platform for explosive monitoring, which is of great significance for providing a new sensing principle for the efficient identification of explosives.

Multifunctional MgO/HKUST-1 Composite for Capture, Catalysis, and Cyclic Cataluminescence Detection of Esters All-In-One to Rapidly Identify Scented Products

The integration of metallic oxide and metal-organic frameworks has attracted considerable attention as obtained composite materials because they show synergistic effects in applications of catalysis and sensing. Herein, we developed the hybrid MgO and HKUST-1 for efficient capture, catalysis, and cyclic cataluminescence (CCTL) detection of esters all-in-one to rapidly identify scented products. The multifunctional MgO/HKUST-1 composite with high CCTL activity was synthesized and characterized. The multifunctional MgO/HKUST-1 composite acts as an enrichment material for ester capture and serves as a catalyst, assisting the analyte to trigger multistage signals. The multistage signals of ester-containing scented products also satisfy the exponential decay equation with a certain τ-value. The τ-values obtained by the CCTL system were applied to identify the brands of essential oils. The working temperature served as the sensor element to obtain various τ-values. The τ-values constituted a digital code to label the different brands of cigarettes with the same aroma type. The multistage signals could be used to distinguish the origin regions of essential oils and tobacco. This work combines the CCTL strategy with the sample pretreatment, opening up a new direction to develop CCL and providing a new platform to rapidly identify ester-containing scented products.

Nanoparticle-based optical sensor arrays

As in many other methods that have integrated nanoparticles (NPs), the chemical nose/tongue strategy has also progressed greatly since the entrance of NPs into this field. The fascinating tunable physicochemical properties of NPs have made them powerful candidates for array-based sensing platforms and have enabled the development of real-time, sensitive and portable systems that are able to target complex mixtures of analytes. In particular, the unique optical properties of NPs have a key role in providing promising array-based sensing approaches. This review will describe the main aspects and processes of most common NP-based optical sensor arrays. The fundamental steps in the design of a sensor array together with details of each step would be provided. The review begins with the principles of optical sensor arrays and presents the concept of cross-reactivity as the main criterion in the selection of sensing elements. Changes in the absorption and emission properties of the assembled sensing elements are categorized into two main classes of optical signals (colorimetric and fluorometric). Popular chemometric methods used for analyzing the data acquired by a sensor array have also been briefly introduced. On the basis of the objective and the desired application, different types of plasmonic and fluorescent NP that possess unique opto-physical properties have been presented as available choices in the design of sensing elements. The vast number of applications of NP-based optical sensor arrays published throughout the literature have then been reviewed according to their mechanism of interaction and the type of optical signal. Finally, the remaining challenges and future directions in this topic have been highlighted.