Homochiral MOF as Chiroptical Sensor for Determination of Absolute Configuration and Enantiomeric Ratio of Chiral Tryptophan

Abstract

The development of a highly selective and sensitive optical method for quantitative enantioselective sensing of chiral amino acids in the presence of other amino acid interferences has remained a major challenge to date. Herein, a homochiral metal–organic framework (MOF), [Zn(L)(2,2′‐bipy)]·H2O (LNNU‐1) (H2L = HOOCC6H4CH2PO(OH)(OC2H5), 2,2′‐bipy = 2,2′‐bipyridine), is designed to interact with tryptophan via multiple noncovalent interactions. The interactions result in the emergence of a strong induced circular dichroism signal. This enables accurate determination of the absolute configuration and enantiomeric ratio of chiral tryptophan in water, mixed natural amino acids, and blood plasma components without any interference from other coexistent species. A simple device with advantageous characteristics of reusability and simple manipulation is designed for enantioselective sensing assay. The obtained results suggest that the rationally designed homochiral MOF is a promising candidate for enantioselective sensing of chiral species.

Zirconium Metal Organic Framework-Based Hybrid Sensors with Chiral and Luminescent Centers Fabricated by Postsynthetic Modification for the Detection and Recognition of Tryptophan Enantiomers

“…Among numerous amino acids, only tryptophan can bind to plasma albumin. 1 Therefore, the detection of free tryptophan in plasma is very meaningful to monitor physical health. The serum environment generally contains D-glucose, L-proline, urea, NaHCO 3 , MgCl 2 , NaCl, KCl, and CaCl 2 .…”

“…Chirality exists widely in nature and is an essential feature of all kinds of life processes. 1 Chiral molecules, also known as enantiomers, are important for many biological or chemical processes. 2 Interestingly, enantiomers possess the same chemical composition but different configurations, which makes them display great differences in pharmacological activities and some metabolic processes or even completely opposite effects.…”

“…3,4 Chiral amino acids are vital components in biological systems, and they are also valuable chiral sources in the territory of catalysis and asymmetric synthesis. 1,5 Two different configurations of amino acid enantiomers both have irreplaceable functions in biology. For example, tryptophan pertains to one of the essential amino acids of the human body, and the process of protein expression is inseparable from the participation of L-tryptophan (L-Trp).…”

Emerging nanosensor platforms and machine learning strategies toward rapid, point-of-need small-molecule metabolite detection and monitoring

“…Through rational design of the recognition sites, chiral MOFs demonstrate huge potential for chiral sensing with greater stereoselective adsorptions due to enhanced, selective metabolite connement from both the MOF scaffold and the conformational rigidity of specic recognition sites. [65][66][67] It is also important to increase the types of MOFs selected (beyond the conventional ZIFs and HKUSTs), as well as explore emerging porous materials such as porous organic polymers (POPs) as potential host matrix candidates, where their integration may enable new performance breakthroughs. 63,68 For instance, besides the water stability of the host porous matrix material, other important considerations include its stability in organic solvents to enable the detection of oil-soluble metabolites.…”

Dual-Functional Metal–Organic Framework for Luminescent Detection of Carcinoid Biomarkers and High Proton Conduction

“…Metal–organic frameworks (MOFs) serve as an important class of crystalline functional materials, synthesized by coordination bonds between metal nodes and various multifunctional linkers, and have exhibited numerous important applications such as catalysis, sensing, separation, magenetism, proton conduction, etc. − In recent years, the construction of multifunctional MOF materials has attracted more and more attention, − especially in luminescence sensing and proton conduction for the dual-functional materials. − Among them, lanthanide-based MOFs (Ln–MOFs) can provide attractive candidatse for the construction of luminescence sensors, because lanthanide centers can exhibit excellent luminescence performances, including extremely high color purity and large Stokes shift as well as a relatively long luminescence lifetime . On the basis of these advantages, luminescent Ln–MOFs have been extensively exploited for the luminescence detection of multiple types of analyses, such as metal cations, inorganic anions, small molecules, amino acid molecules, solvents, gases, explosives, and so forth. − In addition, the organic component of Ln–MOFs is also very important in determining the properties of MOFs.…”