Chiral Recognition with Broad Selective Sensor Arrays

Abstract

The detection and discrimination of chiral analytes has always been a topical theme in food and pharmaceutical industries and environmental monitoring, especially when dealing with chiral drugs and pesticides, whose enantiomeric nature assessment is of crucial importance. The typical approach matches novel chiral receptors designed ad hoc for the discrimination of a target enantiomer with emerging nanotechnologies. The massive synthetic efforts requested and the difficulty of analyzing complex matrices warrant the ever-growing exploitation of sensor array as an alternative route, using a limited number of chiral or both chiral and achiral sensors for the stereoselective identification and dosing of chiral compounds. This review aims to illustrate a little-explored winning strategy in chiral sensing based on sensor arrays. This strategy mimics the functioning of natural olfactory systems that perceive some couples of enantiomeric compounds as distinctive odors (i.e., using an array of a considerable number of broad selective receptors). Thus, fundamental concepts related to the working principle of sensor arrays and the role of data analysis techniques and models have been briefly presented. After the discussion of existing examples in the literature using arrays for discriminating enantiomers and, in some cases, determining the enantiomeric excess, the remaining challenges and future directions are outlined for researchers interested in chiral sensing applications.

Stereospecific Self-Assembly Processes of Porphyrin-Proline Conjugates: From the Effect of Structural Features and Bulk Solvent Properties to the Application in Stereoselective Sensor Systems

“…In the light of the possibility of extending the arena of the involved macrocycles by further functionalisation of both their periphery and their inner core, the presented results are of importance for the development of systems implemented in sensors arrays [ 84 ], are able to discriminate a large class of analytes for the monitoring of food quality [ 85 ], as well as environmental and health safety. According to the data reported in a recent review, in fact, ca.…”

Enantioselective and Chemoselective Optical Detection of Chiral Organic Compounds without Resorting to Chromatography

“…Rapid progress in the development of eIDAs has been made by the group of Anslyn at the University of Texas at Austin, USA and there are a number of commendable publications and all of which cannot be included in this review. However, the readers may study his pioneering contribution in his original papers with other examples of achiral sensor arrays in combination with CD‐spectroscopy, [130a,b] and a few recent reviews, for example, (i) Sedgwick et al ., presented a tutorial review on requirements of an effective IDA along with various design strategies for developing certain specialised IDAs, such as fluorescent indicator displacement assays (FIDAs), reaction‐based indicator displacement assays (RIAs), intramolecular indicator displacement assays (IIDA, though with a very few reports), and quencher displacement assays (QDAs) and covered [131] the extensions of the IDA concept to include eIDAs for determining ee of chiral molecules, (ii) Magna et al ., reviewed [132] the limited number of publications using sensor arrays for the detection of chiral targets, and determination of the enantiomeric excess, with a particular emphasis on the fundamentals and potential of the combined use of chiral and achiral sensing elements for chiral discrimination, along with working principle of sensor arrays and the role of data analysis techniques and models, and (iii) Ansylyn and associates reviewed [133] supramolecular analytical chemistry using optical sensing.…”

Odor Discrimination by Lipid Membranes

“…It is reasonable to hypothesize that these hydrophobic molecules may also accumulate in lipid bilayers. Enantioselectivity is a striking property of the olfactory system, with enantiomeric odorants having distinctly different odors [ 42 ]. Herein, we test the hypothesis that the lipid membranes not only play an elementary structural role for odor receptors but may also participate in odor discrimination.…”