Further Dimensions for Sensing in Biofluids: Distinguishing Bioorganic Analytes by the Salt-Induced Adaptation of a Cucurbit[7]uril-Based Chemosensor

Abstract

Insufficient binding selectivity of chemosensors often renders biorelevant metabolites indistinguishable by the widely used indicator displacement assay. Array-based chemosensing methods are a common workaround but require additional effort for synthesizing a chemosensor library and setting up a sensing array. Moreover, it can be very challenging to tune the inherent binding preference of macrocyclic systems such as cucurbit­[n]­urils (CBn) by synthetic means. Using a novel cucurbit[7]­uril-dye conjugate that undergoes salt-induced adaptation, we now succeeded in distinguishing 14 bioorganic analytes from each other through the facile stepwise addition of salts. The salt-specific concentration-resolved emission provides additional information about the system at a low synthetic effort. We present a data-driven approach to translate the human-visible curve differences into intuitive pairwise difference measures. Ion mobility experiments combined with density functional theory calculations gave further insights into the binding mechanism and uncovered an unprecedented ternary complex geometry for CB7. TThis work introduces the non-selectively binding, salt-adaptive cucurbit­[n]­uril system for sensing applications in biofluids such as urine, saliva, and blood serum.

Fluorophore-based host–guest assembly complexes for imaging and therapy

“…30). 135 This work presents a non-selective binding of a salt-adapted melon-urinary system for sensing biological fluids such as urine, saliva, and serum. Therefore, compared to conventional clinical methods, a supramolecular fluorescent system based on host–guest assembly is a new reliable method for detecting markers in biological fluids.…”

A supramolecular fluorescence array sensor for toxic heavy metal ion detection in environmental water and rice seedling extracts

“…[24][25][26][27][28][29] Therefore, a sensing array can be designed based on the cross-reactivity of the interaction between the fluorescent probe derived from cucurbit[n]uril and the analyte. The use of supramolecular array sensors based on cucurbit[n]uril to detect and recognize multi-target analytes, such as bioactive metabolites, [30][31][32] environmental pollutants, 33 and pesticide residues, 34 has received considerable attention.…”

Supramolecular Fluorescence Sensor Array Based on Cucurbit[8]uril Complexes Used for the Detection of Multiplex Quaternary Ammonium Pesticides

“…Supramolecular sensor arrays have the advantage of detecting analytes and removing pollutants in complex mixtures, for example, some difficult detection tasks such as explosives, metal ions and anions, and biomarkers for cancer and disease have been achieved using supramolecular sensor arrays. 16−18 21 Biedermann and co-workers reported a fluorescence sensor microarray for sensing spermine, cadaverine, and amantadine based on a Q[n]/indicator system. 22 Our group reported a fluorescence sensor array based on three Q [7]@dye complexes used to recognize and detect metal ions in a previous study.…”