Development of “Imprint-and-Report” Dynamic Combinatorial Libraries for Differential Sensing Applications

Abstract

Sensor arrays using synthetic receptors have found great utility in analyte detection, resulting from their ability to distinguish analytes based on differential signals via indicator displacement. However, synthesis and characterization of receptors for an array remain a bottleneck in the field. Receptor discovery has been streamlined using dynamic combinatorial libraries (DCLs), but the resulting receptors have primarily been utilized in isolation rather than as part of the entire library, with only a few examples that make use of the complexity of a library of receptors. Herein, we demonstrate a unique sensor array approach using "imprint-and-report" DCLs that obviates the need for receptor synthesis and isolation. This strategy leverages information stored in DCLs in the form of differential library speciation to provide a high-throughput method for both developing a sensor array and analyzing data for analyte differentiation. First, each DCL is templated with analyte to give an imprinted library, followed by in situ fluorescent indicator displacement analysis. We further demonstrate that the reverse strategy, imprinting with the fluorescent reporter followed by displacement with each analyte, provides a more sensitive method for differentiating analytes. We describe the development of this differential sensing system using the methylated Arg and Lys post-translational modifications (PTMs). Altogether, 19 combinations of 3−5 DCL data sets that discriminate all 7 PTMs were identified. Thus, a comparable sensor array workflow results in a larger payoff due to the immense information stored within multiple noncovalent networks.

A facile way to construct sensor array library via supramolecular chemistry for discriminating complex systems

“…Subsequent introduction of the analyte causes displacement of the indicator from the receptor to produce a measurable output signal. IDA is compatible with differential sensing, because an array can be constructed by combining multiple receptors and indicators without additional synthetic efforts 6 , 58 . In this study, the indicators are six fluorescent dyes (Fig.…”

Covalent Chemical Tools for Profiling Post-Translational Modifications

“…The design mimicked aromatic cages found in proteins, with the major drivers of recognition being electrostatic and non-classical hydrophobic interactions. Since then, diverse versions of synthetic receptors have been introduced (Corbett et al, 2008;Li C. et al, 2013;Peacock et al, 2016 host-guest interplay which subsequently leads to interpretable signals for different methylated states of lysine and arginine (Harrison et al, 2021) (Figure 2C).…”

“…Similarly, Li et al and Peacock et al utilized a negatively charged carboxyatopillar [5] arene and tetracyanoresorcin [4] arene receptor to bind to basic and positively charged amino acid residues and trimethyllysine peptides. Just recently, Waters et al developed the “imprint and report” technology that utilizes building blocks that form reversible covalent bonds as a templating platform to facilitate a host-guest interplay which subsequently leads to interpretable signals for different methylated states of lysine and arginine ( Harrison et al, 2021 ) ( Figure 2C ).…”

Application of an Imprint‐and‐Report Sensor Array for Detection of the Dietary Metabolite Trimethylamine N‐Oxide and Its Precursors in Complex Mixtures

“…This differential binding generates unique colorimetric or fluorescent patterns for outputs, which can be visualized via principal component analysis (PCA) [28, 29] . We have previously described an advancement in the field of sensor arrays that provides a high‐throughput method for differentiating post‐translational modifications (PTMs) in histone peptides, including all the methylation states of lysine and arginine [30] . We refer to this systems chemistry approach as “imprint‐and‐report” sensing as it uses templated, non‐equilibrating, or “imprinted,” dynamic combinatorial libraries (DCLs) [31] to create a unique fluorescence pattern report for each analyte.…”

“…Combined data from several DCLs and analytes creates analyte differentiation based on pattern recognition (Figure 2b). While others have reported the use of mixtures containing multiple hosts and indicators for differential sensing, [32–34] our method eliminates the need to develop and isolate new receptors that bind analytes of interest, since they are instead generated in situ [30] . This allows us to leverage the vast amount of chemical information that is stored in an imprinted DCL relative to a single host–guest interaction.…”