Recognition-Enabled Automated Analyte Identification via ¹⁹F NMR

Abstract

Nuclear magnetic resonance (NMR) is an indispensable tool for structural elucidation and noninvasive analysis. Automated identification of analytes with NMR is highly pursued in metabolism research and disease diagnosis; however, this process is often complicated by the signal overlap and the sample matrix. We herein report a detection scheme based on 19 F NMR spectroscopy and dynamic recognition, which effectively simplifies the detection signal and mitigates the influence of the matrix on the detection. It is demonstrated that this approach can not only detect and differentiate capsaicin and dihydrocapsaicin in complex realworld samples but also quantify the ibuprofen content in sustainedrelease capsules. Based on the 19 F signals obtained in the detection using a set of three 19 F probes, automated analyte identification is achieved, effectively reducing the odds of misrecognition caused by structural similarity.

Improving the Sensitivity of Enantioanalysis with Densely Fluorinated NMR Probes

“…Previously, our research group and others have been actively involved in the advancement of NMR-based detection techniques, with a focus on achieving high sensitivity and enhanced resolving ability by using 19 F NMR. − One of our approaches involves leveraging the dynamic recognition properties of the NMR probe to convert analyte binding events into 19 F NMR signals with distinct chemical shifts. This strategy, which produces a chromatogram-like output, is often referred to as recognition-enabled chromatographic (REC) NMR. , Based on the unique chemical reactivity of the hypervalent iodine compound, we develop an efficient method for the introduction of nonafluoro- tert -butoxy groups into arenes .…”

19F‐Labeled Probes for Recognition‐Enabled Chromatographic 19F NMR

“…To obtain 19 F-labeled probes with orthogonal resolving abilities, we decorated the C 3 symmetrical skeleton of the aluminum-trisphenolate complex with different fluorinated moieties (Figure 11, 12). [40] By using a probe array constructed by probes 8, 9, and 10, a database was built up for interested analytes using the simplified and characteristic 19 F NMR signals. This multiprobe strategy allows analytes with minimal structural differences to be distinguished with high fidelity.…”

“…This limitation hampers the widespread utilization of 19 F NMR as a general analytical technique. Our approach to addressing this limitation is to use dedicatedly designed 19 F‐labeled probes that can reversibly bind to the target analyte [27–30,39,40] . A similar recognition‐based scheme is widely adopted in the creation of fluorescent sensors, where the recognition event is sensed by the intensity change of an optical signal (Figure 1A).…”

“…Our approach to addressing this limitation is to use dedicatedly designed 19 F-labeled probes that can reversibly bind to the target analyte. [27][28][29][30]39,40] A similar recognition-based scheme is widely adopted in the creation of fluorescent sensors, where the recognition event is sensed by the intensity change of an optical signal (Figure 1A). [41][42][43][44][45] However, these intensity-based approaches are usually not amenable to multicomponent analysis.…”

“…(A-K)19 F NMR spectra were recorded at a Larmor frequency of 564 MHz. (A-K) Reproduced with permission from the reference[40]. Copyright 2022, American Chemical Society.…”