Screening and Discrimination of Perfluoroalkyl Substances in Aqueous Solution Using a Luminescent Metal–Organic Framework Sensor Array

Abstract

The extensive production and large-scale use of perfluoroalkyl substances (PFASs) have raised their presence in aquatic environments worldwide. Thus, the facile and reliable screening of PFASs in aqueous systems is of great significance. Herein, we designed a novel fluorescent sensor array for the rapid screening and discrimination of multiple PFASs in water. The sensor array comprised three highly stable zirconium porphyrinic luminescent metal−organic frameworks (i.e., PCNs) with different topological structures. The sensing mechanism was based on the static fluorescence quenching of PCNs by PFASs upon their adsorptive interactions. The fluorescence response patterns were characteristic for each PFAS because of their different adsorption affinities toward different PCNs. Through the interpretation of response patterns by statistical methods, the proposed PCN array successfully discriminated six different kinds of PFASs, each PFAS at different concentrations and PFAS mixtures at different molar ratios. The practicability of this array was further verified by effectively discriminating PFASs in two real water samples. Remarkably, the PCN sensors exhibited a very short response time toward PFASs (within 10 s) due to the ordered pore structure allowing fast PFAS diffusion. This study not only provides a facile method for rapid PFAS screening in waters but also broadens the application of luminescent metal−organic frameworks and array techniques in sensing fields.

Advances in Optical Sensors for Persistent Organic Pollutant Environmental Monitoring

“…Chen et al developed a sensor array to detect perfluoroalkyl substances (PFASs) in water [ 110 ]. The wide use of PFAS in the industrial field results in a large release of these pollutants into the water due to their good solubility, and today, these contaminants represent a threat to humanity due to their toxicity.…”

“…( d ) LDA canonical score plot derived from fluorescence responses of PCN array toward standard (gray) and test (red, blue, and green) mixtures of PFOA and PFDA in surface water. Image is rearranged from Figures 2c, 3b,c and 7a of [ 110 ].…”

Towards Solving the PFAS Problem: The Potential Role of Metal‐Organic Frameworks

“…In a recent study performed by Chen et al., the promise of optical sensing of PFAS by a fluorescent MOF array was demonstrated [76] . The sensor array consisted of three zirconium‐based porphyrinic coordination networks (PCNs (PCN‐222, PCN‐223, and PCN‐224) to sense and discriminate different mixtures of PFAS in both surface and underground water samples.…”

“…In a recent study performed by Chen et al., the promise of optical sensing of PFAS by a fluorescent MOF array was demonstrated. [76] The sensor array consisted of three zirconium‐based porphyrinic coordination networks (PCNs (PCN‐222, PCN‐223, and PCN‐224) to sense and discriminate different mixtures of PFAS in both surface and underground water samples. The MOF sensing array was used to distinguish between six different PFAS by producing a unique fluorescent response pattern for each species, depending on their adsorptive interaction with the MOFs.…”

Detection and differentiation of per- and polyfluoroalkyl substances (PFAS) in water using a fluorescent imprint-and-report sensor array

“…[31][32][33][34][35] Among the most successful examples thus far are the use of aggregation-induced emission luminogens assembled on a chip that can detect PFOA and PFOS as low as 100 nM reported by Fang et al, 36 and an indicator displacement assay (IDA) using a guanidinocalix [5]arene and uorescein to detect PFOA and PFOS with limits of detection (LODs) of 26.4 nM and 21.4 nM, respectively, developed by Zheng et al 37 Sensor arrays have previously been developed as a facile method of detecting and distinguishing several analytes with similar structures from one another using pattern recognition, [38][39][40][41] but only a couple of sensor arrays for PFAS currently exist. 42,43 Typically, developing a sensor array involves identifying and synthesizing a set of hosts that exhibit differential binding proles towards the analytes and colorimetric or uorescent reporter(s). When the reporter(s) and analytes are in competition with one another for binding to each host, a unique pattern of outputs is obtained, allowing for visual differentiation via the statistical tool principal component analysis (PCA).…”