Improving Covalent Organic Frameworks Fluorescence by Triethylamine Pinpoint Surgery as Selective Biomarker Sensor for Diabetes Mellitus Diagnosis

Abstract

The nitrogen-containing imine or hydrazone linked covalent organic frameworks (COFs) are poorly luminescent due to the fluorescence quenching by nitrogen atoms in the linkages, even if highly luminescent units and linkers are employed. The fluorescence quenching pathway to prevent linkage-originated to mitigate the inherent limitations of the linkage is a promising method for luminescent COFs. The generation of N– by deprotonation of the N–H unit eliminates the electron transfer from N lone pair to COF (TpPa-1) and enhances the luminescence. In this work, TpPa-1 achieved turn-on luminescence response with good sensitivity and reproducibility toward triethylamine (TEA) vapor in the process of deprotonation. The fabricated detector offers a viable approach for sensing ppm-level TEA, which can remind people to take timely measures to reduce the environmental hazards caused by TEA. The fluorescent sensor TpPa-1@LE constructed by the products of TpPa-1 and TEA can quantitatively trace biomarker methylglyoxal (MGO) for diabetes mellitus diagnosis in serum system. Furthermore, using TEA and MGO as input signals and the two fluorescence emissions G476 and Y525 as output signals, an advanced analytical device based on two Boolean logic gates with INH and AND function is constructed. This work provides a new strategy for improving the weak luminescence of COF in aqueous solution and realizes selective response to biomarker (MGO) for diabetes mellitus diagnosis.

Optoelectronic processes in covalent organic frameworks

“…By the implementation of two logic gates, the red-shifted fluorescence upon MGO exposure can be directly traced as an output signal, leading to an easy read-out diagnostic device. 213 The above examples illustrate the main strategies developed so far to demonstrate chemical sensing with COFs. Similar applications of COFs based on these principles have been reported for numerous additional analytes but will not be discussed here.…”

Room-temperature preparation of a chiral covalent organic framework for the selective adsorption of amino acid enantiomers

“…Covalent organic frameworks (COFs) 19,20 are crystalline organic porous materials with broad applications in diverse elds including chromatography separation, 21,22 heterogeneous catalysis, 23,24 uorescence sensing 25,26 and optoelectronic materials. 27,28 The large surface area, excellent stability and the number of duplicate ordered units of COFs allow numerous interactions between the host and guests, such as hydrogen bonding, p-p interactions, hydrophobic interactions and molecular sieving, indicating COFs as a convenient platform for enantioselective adsorption.…”

Research Progress in Covalent Organic Frameworks for Photoluminescent Materials

“…Adapted with permission from refs. [53, 57], copyright American Chemical Society, and ref. [29], copyright Wiley‐VCH.…”

“…[56] Yana nd Wang reported aC OF (TpPa-1) with weak luminescence, which was synthesised through the Schiff base reactiono ft riformylphloroglucinol and p-phenylenediamine for detecting ab iomarker of diabetes mellitus( Figure 9C). [57] The NÀHg roup of TpPa-1 can be deprotonated by the Lewis base TEA to form anionic nitrogen, which can reduce the nitrogen-induced FL quenching pathway ( Figure 9D). The generation of an itrogenbased anion by deprotonation of the NÀHl inkage decreases electron transfer from the lone pair of nitrogen to the framework and improves the luminescence.…”