A rapid and efficient way to dynamic creation of cross-reactive sensor arrays based on ionic liquids.

Based on the simple counterion exchange of ionic liquids, a rapid, facile, and efficient strategy to create a cross-reactive sensor array with a dynamic tunable feature was developed, and exemplified by the construction of a sensor array for the identification and classification of nitroaromatics and explosives mimics. To achieve a good sensing system with fast response, good sensitivity, and low detection limit, the synthesized ionic liquid receptors were tethered onto a silica matrix with a macro-mesoporous hierarchical structure. Through the facile anion exchange approach, abundant ionic-liquid-based individual receptors with diversiform properties, such as different micro-environments, diverse molecular interactions, and distinctive physico-chemical properties, were easily and quickly synthesized to generate a distinct fingerprint of explosives for pattern recognition. The reversible anion exchange ability further endowed the sensor array with a dynamic tunable feature as well as good controllability and practicality for real-world application. With the assistance of statistical analysis, such as principal component analysis (PCA) and linear discrimination analysis (LDA), an optimized-size array with a good resolution was rationally established from a large number of IL-based receptors. The performed experiments suggested that the ionic-liquid-based sensing protocol is a general and powerful strategy for creating a cross-reactive sensor array that could find a wide range of applications for sensing various analytes or complex mixtures.