Selective Recognition Research Articles

Real-time, noise and drift resilient formaldehyde sensing at room temperature with aerogel filaments

Formaldehyde, a known human carcinogen, is a common indoor air pollutant. However, its real-time and selective recognition from interfering gases remains challenging, especially for low-power sensors suffering from noise and baseline drift. We report a fully 3D-printed quantum dot/graphene-based aerogel sensor for highly sensitive and real-time recognition of formaldehyde at room temperature. By optimizing the morphology and doping of printed structures, we achieve a record-high and stable response of 15.23% for 1 part per million formaldehyde and an ultralow detection limit of 8.02 parts per billion consuming only ∼130-microwatt power. On the basis of measured dynamic response snapshots, we also develop intelligent computational algorithms for robust and accurate detection in real time despite simulated substantial noise and baseline drift, hitherto unachievable for room temperature sensors. Our framework in combining materials engineering, structural design, and computational algorithm to capture dynamic response offers unprecedented real-time identification capabilities of formaldehyde and other volatile organic compounds at room temperature.

DNAzyme 10-23 - Based Nanomachines for Nucleic Acid Recognition.

DNAzyme-based nanomachines (DNM) for the detection of DNA and RNA sequences (analytes) are multifunctional structures made of oligonucleotides. Their functions include tight analyte binding, highly selective analyte recognition, fluorescent signal amplification by multiple catalytic cleavages of a fluorogenic reporter substrate, and fluorogenic substrate attraction for an increase in sensor response. Functional units are attached to a common DNA scaffold for their cooperative action. The RNA-cleaving 10-23 DNMs featureimproved sensitivity in comparison with non-catalytic hybridization probes. The stability of the DNM and the increased chances of substrate recognition are providedby a double-stranded DNA fragment,a tile. DNM can differentiate two analytes with a single nucleotide difference in a folded RNA and a double-stranded DNA and detect analytes at concentrations ~1000 times lower than other protein-free hybridization probes. This article presents the concept behind the diagnostic potential of DNA-nanomachine activity and overviews DNM design, assembly, and applicationin nucleic acid detection assays.

The RNA-Binding Domain of hnRNP U Extends beyond the RGG/RG Motifs.

Heterogeneous nuclear ribonucleoprotein U (hnRNP U) is a ubiquitously expressed protein that regulates chromatin architecture through its interactions with numerous DNA, protein, and RNA partners. The RNA-binding domain (RBD) of hnRNP U was previously mapped to an RGG/RG motif within its disordered C-terminal region, but little is understood about its binding mode and potential for selective RNA recognition. Analysis of publicly available hnRNP U enhanced UV cross-linking and immunoprecipitation (eCLIP) data identified high-confidence binding sites within human RNAs. We synthesized a set of diverse RNAs encompassing 11 of these identified cross-link sites for biochemical characterization using a combination of fluorescence anisotropy and electrophoretic mobility shift assays. These in vitro binding experiments with a rationally designed set of RNAs and hnRNP U domains revealed that the RGG/RG motif is a small part of a more expansive RBD that encompasses most of the disordered C-terminal region. This RBD contains a second, previously experimentally uncharacterized RGG/RG motif with RNA-binding properties comparable to those of the canonical RGG/RG motif. These RGG/RG motifs serve redundant functions, with neither serving as the primary RBD. While in isolation, each RGG/RG motif has modest affinity for RNA, together they significantly enhance the association of hnRNP U with RNA, enabling the binding of most of the designed RNA set with low to midnanomolar binding affinities. Identification and characterization of the complete hnRNP U RBD highlight the perils of a reductionist approach to defining biochemical activities in this system and pave the way for a detailed investigation of its RNA-binding specificity.

Zinc(II)-MOF: A Versatile Luminescent Sensor for Selective Molecular Recognition of Flame Retardants and Antibiotics.

An exceptional Zinc(II)-organic framework with the formula [{Zn(L4-py)(bdc)}·DMF]n (Zn-MOF) has been constructed solvothermally using a novel linker L4-py {2,7-bis(3-(pyridin-4-ylethynyl)phenyl)benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone}, coligand H2bdc (1,4-benzenedicarboxylic acid), and ZnBF4·xH2O. The ligand L4-py has been fabricated after functionalization of NDA (1,4,5,8-naphthalenetetracarboxylic dianhydride) core with 3-(pyridin-4-ylethynyl)phenyl group. The single-crystal X-ray analysis reveals that Zn-MOF exhibits a comprehensive three-dimensional (3D) framework architecture and features (4)-connected uninodal dia; 4/6/c1; sqc6 topology with point symbol {66} and two-dimensional (2D) + 2D, parallel polycatenation. Notably, Zn-MOF displayed excellent fluorescence phenomenon and stability in water as well as in methanol solvents and was harnessed as a versatile sensor, demonstrating selective and sensitive molecular recognition of flame retardants and antibiotics. Notably, Zn-MOF displayed 57 and 49.5% quenching efficiency for the flame-retardant pentabromophenol (PBP) and 3,3',5,5'-tetrabromobisphenol A (TBPA), respectively. Whereas an outstanding 90% quenching efficiency was observed for antibiotics, tetracycline (TC) and secnidazole (SD). The mechanistic investigations of this luminescence quenching suggest that this might be primarily occurring via the Fourier resonance energy transfer (FRET) and photoinduced electron transfer (PET) mechanisms, which might be assisted by the competitive absorption and host-guest interactions. The π-electron-rich framework structure of sensor Zn-MOF activates this mechanism.

Integrating molecular imprinting into flexible covalent organic frameworks for selective recognition and efficient extraction of aflatoxins

Covalent organic frameworks (COFs) are promising adsorbents for extraction, but their selectivity for molecular recognition remains a challenging issue due to the very limited structural design with rigid structure. Herein, we report an elegant strategy for the design and synthesis of molecularly imprinted flexible COFs (MI-FCOFs) via one-pot reaction between the flexible building block of 2,4,6-tris(4-formylphenoxy)− 1,3,5-triazine and linear 4-phenylenediamine for selective extraction of aflatoxins. The flexible chain structure enabled the developed MI-FCOF to adjust the shape and conformation of frameworks to suit the template molecule, giving high selectivity for aflatoxins recognition. Moreover, MI-FCOF with abundant imprinted sites and function groups exhibited an exceptional adsorption capacity of 258.4 mg g−1 for dummy template which is 3 times that of no-imprinted FCOF (NI-FCOF). Coupling MI-FCOF based solid-phase extraction with high-performance liquid chromatography gave low detection limits of 0.003–0.09 ng mL−1 and good precision with relative standard deviations ≤ 6.7% for the determination of aflatoxins. Recoveries for the spiked rice, corn, wheat and peanut samples were in the range of 85.4%− 105.4%. The high selectivity of the developed MI-FCOF allows matrix-free determination of AFTs in food samples. This work offers a new way to the design of MI-FCOF for selective molecular recognition.

Bacterial Cellulose-Based MOF Hybrid as a Sensitive Switch Off-On Luminescent Sensor for the Selective Recognition of l-Histidine.

In this study, a stable and luminescent UiO-66-NH2 (UN) and its derivative Cu2+@UN were prepared and utilized successfully as an Off-On luminescent sensing platform for effective, selective, as well as rapid (5 min) detection of l-Histidine (l-His). The UN reveals efficient quenching in the presence of Cu2+ ions through photoinduced electron transition (PET) mechanism as a dynamic quenching process (in the range of 0.01-1 mM) forming Cu2+@UN sensing platform. However, due to the remarkable affinity between l-His and Cu2+, the luminescence of Cu2+@UN is recovered in the presence of l-His indicating Turn-On behavior via a quencher detachment mechanism (QD). A good linear relationship between the l-His concentration and luminescence intensity was observed in the range of 0.01-40 μM (R2 = 0.9978) with a detection limit of 7 nM for l-His sensing. The suggested method was successfully utilized for l-His determination in real samples with good recoveries and satisfying consequences. Moreover, the result indicates that only l-His induces a significant luminescence restoration of Cu2+@UN and that the signal is significantly greater than that of the other amino acids. Also, the portable test paper based on bacterial cellulose (BC) as the Cu2+@UNBC sensing platform was developed to conveniently evaluate the effective detection of l-His.

Bonding to Psychedelics: Synthesis of Molecularly Imprinted Polymers Targeting 4-Bromo-2,5-dimethoxyphenethylamine (2C-B)

The increasing interest in utilizing psychedelics for therapeutic purposes demands the development of tools capable of efficiently monitoring and accurately identifying these substances, thereby supporting medical interventions. 4-Bromo-2,5-dimethoxyphenethylamine (2C-B) has gained significant popularity as one of the most widely used psychedelic compounds in non-medical settings. In this study, we aimed to create a material with selective recognition of 2C-B by synthesizing a series of molecularly imprinted polymers (MIP) using 2C-B as the template and varying ratios of methacrylic acid (MAA) as the functional monomer (1:2, 1:3, and 1:4). Both thermal and microwave-assisted polymerization processes were employed. The molar ratio between the template molecule (2C-B) and functional monomer (MAA) was 1:4, utilizing a microwave-assisted polymerization process. Isotherm studies revealed a Langmuir’s maximum absorption capacity (Bmax) value of 115.6 μmol·mg−1 and Kd values of 26.7 μM for this material. An imprint factor of 4.2 was determined for this material, against the corresponding non-imprinted polymer. The good selectivity against 14 other new psychoactive substances highlighted the material’s potential for applications requiring selective recognition. These findings can contribute to the development of tailored materials for the detection and analysis of 2C-B, supporting advancements in non-medical use monitoring and potential therapeutic models involving psychedelics.

Fluorescent bacterial cellulose@Zr-MOF via in-situ synthesis for efficient enrichment and sensitive detection of Cr(VI)

In this study, for the first time, a new Zr-metal–organic framework (MOF) with strong aggregation-induced emission was successfully grown on bacterial cellulose (BC) using an in situ synthesis method, yielding the fluorescent composite nanofiber BC@Zr-MOF. The BC with abundant hydroxyl groups, which can be uniformly wrapped in the interior of the MOF layer to form BC@Zr-MOF, was used as the growth template. The resulting composite nanofibers had a higher specific surface area (1, 116 m2/g), stronger fluorescence emission and better pH stability than MOF particles. In addition, BC@Zr-MOF exhibited selective recognition and enrichment of Cr2O72− in the aqueous phase and a high adsorption capacity of 90 mg/g. Moreover, because of the high aspect ratio and good tensile strength (6.73 N/mm2), BC@Zr-MOF nanofibers could be readily made into freestanding nanopapers via vacuum filtration, thus solving the molding and recycling problems of MOFs. The facilely prepared test paper could rapidly, sensitively and selectively detect Cr2O72− with the limit of detection (LOD) of 41.8 nM, which is nearly 500 times lower than that of the national drinking water standard. Moreover, the LOD of BC@Zr-MOF nanopapers, when used in combination with circulating filtration, decreases to 6.9 nM owing to the adsorption-enrichment effect.

Selective Recognition of Aromatic Amino Acids by a Molecular Cleft in Water

AbstractThe development of water‐soluble hosts for the selective recognition of aromatic amino acids is highly desirable and may serve as a tool to facilitate drug discovery and enable fabrication of sensors for point‐of‐care monitoring in the context of phenylketonuria disease. This paper presents the synthesis and characterization of a water‐soluble molecular cleft which is demonstrated to selectively bind aromatic amino acid guests over other amino acids in aqueous medium, favoring ʟ‐Trp over ʟ‐Phe and ʟ‐Tyr by a factor of approximately five. Host/guest‐interaction forces were studied by 1H‐NMR titrations complemented by fluorescence titrations and isothermal titration calorimetry. The here presented results provide a starting point for future optimizations in our efforts to selectively identify and quantify individual aromatic amino acids in aqueous medium.

Facile and fast fabrication of magnetic molecularly imprinted polymer for extraction of carbamazepine from environmental samples and fish tissues followed by UHPLC-MS/MS detection

A rapid synthesis of carbamazepine (CBZ) magnetic molecularly imprinted polymer (MMIP) was proposed based on reflux precipitation polymerization method. The synthesis time for the formation of MIP coating on MMIP was shortened to less than 4 h. The characterization of MMIP demonstrates the successful synthesis of the imprinted layer. The adsorption selectivity of MMIP was systematically evaluated and showed fast selective recognition for CBZ. The MMIP based magnetic solid-phase extraction (MSPE) combined with UHPLC-MS/MS was developed, and its feasibility was validated in four complex matrices of environmental water, sediment, fish muscle and liver. It was successfully applied for the analysis of environmental water, sediment, and different fish tissues. Four environmental water samples from different sampling sites were found to contain CBZ at concentrations < LOD or LOQ, while the sediment samples collected at the same location did not contain CBZ. Two out of three wild snakeheads were found to contain CBZ, and the liver showed the highest residue. The study of drug exposed snakeheads indicate CBZ tends to accumulate in liver, followed by brain, heart and kidneys, and finally muscle and gills. The proposed method displays high potential for analyzing CBZ in complex environmental and biological samples.

Two helical Schiff bases with “AIE+ESIPT” characteristics exhibiting selective ion recognition properties

Two racemic Schiff bases (H4L1 and H4L2) were synthesized and characterized, and the crystal structures indicated their helical configurations with equal amounts of P- and M-helicity. The aggregation-induced emission (AIE) and selective ion recognition properties of H4L1 and H4L2 were investigated using UV–vis absorption and fluorescence spectra. The results showed that both H4L1 and H4L2 exhibited obvious “AIE + ESIPT” characteristics in THF/H2O solution upon increasing the water fraction. Both H4L1 and H4L2 displayed an obvious turn-off fluorescence response to Cu2+ and F−, and a slight turn-off response to Fe3+ in DMSO, while they displayed an efficient selective ion recognition of Cu2+ in THF/H2O (1: 1, V/V). The corresponding stoichiometry ratio, association constant, Stern-Volmer quenching constant, and the detection limits were determined via Job's plots, UV–vis spectra titration as well as fluorescence spectra titration experiments. The crystal structures of the complexes obtained from the interactions of H4L1 with Cu2+ and Fe3+ illustrated their binding modes and binding differences, which helped us interpret the ion recognition mechanism of H4L1 and H4L2. In addition, the application of H4L2 on test strips was performed, indicating that H4L2 can be used for the rapid detection of Cu2+ and F− in THF. The acid-responsive fluorescence behavior of H4L2 showed that the white light emission can be obtained upon the addition of hydrochloric acid or aldehyde c into H4L2.

Molecular Dynamics Simulation of the Adsorption and Diffusion of C8 Aromatic Isomers in MIL-47(V).

The separation of C8 aromatic isomers (oX: o-xylene, pX: p-xylene, mX: m-xylene, and EB: ethylbenzene) remains an enormous challenge in industrial production due to their similar molecular structures and physical properties. Porous materials with suitable pore structures and selective recognition sites to discriminate the slight structural differences of isomers are imminently needed. In this paper, MIL-47(V) with a three-dimensional (3D) grid structure of 10.5 × 10.5 Å2 and a one-dimensional (1D) diamond channel was selected as the adsorbent. However, the mechanism of the adsorption and separation of C8 aromatic isomers in porous materials still needs to be understood. Given the importance of C8 aromatic isomers' confinement in MIL-47(V) for adsorption and diffusion applications, it is important to understand C8 aromatic isomers' behavior in MIL-47(V). Here, we demonstrated from a simulation perspective that metal-organic frameworks MIL-47(V) with one-dimensional (1D) diamond channels can identify C8 aromatic isomers. Molecular dynamics (MD) simulations have shown that organic ligands with guest response sites of MIL-47(V) can effectively distinguish between C8 aromatic isomers by adaptation to the shape of a specific isomer. MIL-47(V) has high adsorption and an excellent separation sequence between C8 aromatic isomers: oX > pX ≈ mX > EB. Significant differences exist in π-π superposition interactions between C8 aromatic isomers and between C8 aromatic isomers and the skeletons. This phenomenon is mainly caused by the unique pore structure and guest response characteristics of MIL-47(V). This work is identified as a supplementary instruction to experimental research and is expected to provide profound insights into research on developing C8 aromatic isomers' adsorption and separation and theoretical support.

Selective recognition and extraction of iodide from pure water by a tripodal selenoimidazol(ium)-based chalcogen bonding receptor

A selenium-based tripodal chalcogen bond (ChB) donor TPI-3Se is demonstrated for the recognition and extraction of I- from 100% water medium. NMR and ITC studies with the halides reveal that the ChB donor selectively binds with the large, weakly hydrated I-. Interestingly, I- crystallizes out selectively in the presence of other halides supporting the superiority of the selective recognition of I-. The X-ray structure of the ChB-iodide complex manifests both the μ1 and μ2 coordinated interactions, which is rare in the C-Se···I chalcogen bonding. Furthermore, to validate the selective I- binding potency of TPI-3Se in pure water, comparisons are made with its hydrogen and halogen bond donor analogs. The computational analysis also provides the mode of I- recognition by TPI-3Se. Importantly, this receptor is capable of extracting I- from pure water through selenium sigma-hole and I- interaction with a high degree of efficiency (∼70%).

SERS aptasensor utilizing aptamer-conformation-mediated regulation of Au dumbbell dimers for the ultrasensitive detection of β-phenethylamine in foods

Surface-enhanced Raman spectroscopy (SERS) is a powerful tool for the detection of target analytes in foods, with the realization of “hot spots” between plasmonic metal nanoparticles (NPs) being critical for ultrasensitive detection. Herein, we proposed a new aptamer conformation-mediated SERS “hot spots” strategy. Au NPs were functionalized with strands of complementary DNA containing β-phenethylamine aptamers and the Raman reporter 4-mercaptobenzonitrile (4-MBN). This allowed DNA-driven self-assembly of an Au dumbbell dimer-based SERS aptasensor for the detection of the β-phenethylamine. After selective recognition of β-phenethylamine by the aptamer, the aptamer folded, bringing AuNPs in the dimers close together to create SERS “hot spots”. This produced an intense SERS signal in the “biologically silent” region for 4-MBN (2225 cm−1), the intensity of which increased linearly with the logarithm of the β-phenethylamine concentration. Under the optimized conditions, the linear range of SERS aptasensor was 10−6 to 10−2 mg L−1, with a low limit of detection of 3.8 × 10−7 mg L−1. Further, the developed SERS aptasensor was successfully employed to determine the β-phenethylamine in a range of food samples, with the results being identical to those obtained using a high-performance liquid chromatography method.

A bearing fault diagnosis method with improved symplectic geometry mode decomposition and feature selection

A rolling bearing fault diagnosis method based on improved symplectic geometry mode decomposition (SGMD) and feature selection was proposed to solve the problem of low fault identification due to the influence of noise on early bearing fault features. First, the SGMD SGMD is improved to enhance its robustness in decomposing signals with noise, then the time domain, frequency domain, and time-frequency features of each symplectic geometric component are extracted as feature vectors. Second, a comprehensive feature selection strategy is proposed to select the optimal subset of features that are conducive to fault classification. Finally, considering the problem of low classification accuracy of a single machine learning model, the AdaBoost-WSO-SVM model is constructed for fault classification using the AdaBoost algorithm of integrated learning. Experimental decomposition of complex signals with noise indicates that the improved SGMD is more effective compared to traditional SGMD. Subsequently, multiple experiments were conducted using the bearing datasets from Case Western Reserve University (CWRU) and Jiangnan University (JNU). The experimental results reveal that, after comprehensive feature selection and ensemble learning pattern recognition experiments on the CWRU dataset, the average accuracy of fault diagnosis can reach 99.67%. On the JNU dataset, the proposed fault diagnosis method achieves an average accuracy of 95.03%. This suggests that, compared to other feature selection methods and classification models, the proposed approach in this paper exhibits higher accuracy and generalization capabilities.

Engineering flower-shaped hierarchical micromotors on a sustainable biotemplate by teamed boronate affinity-based surface imprinting for effective separation of shikimic acid

Self-propelled nano/micromotors are the frontier of separation materials because they are capable of converting external energy in the surrounding environment into kinetic energy for their autonomous movement. In this work, a bioinspired flower-shaped hierarchical teamed boronate affinity (TBA)-imprinted Pt-free micromotor is introduced based on waste rape pollen as a biotemplate due to its merits of sustainability, rich source and low price. Such micromotor, composed of MnO2 nanosheets as a catalytic medium, Mg-Al layered double hydroxides (LDH) nanosheets as large surface area substrate and functional surface imprinted polymers as identification subject, exhibits autonomic motor behavior powdered by oxygen bubbles generated by the decomposition of H2O2 and selective recognition and separation for shikimic acid (SA). The hierarchical flower-shaped structure affords more accessible recognition sites for SA, which thus facilitates the separation process. Moreover, in combination with the TBA strategy, the micromotor can precisely recognize the target via boronate affinity between boronic acids and cis-diols from SA while showing strong binding capacity under neutral conditions. Benefiting from the pluripotent role of pioneering boronate affinity-covalent imprinted technique, hydrogen bonds interaction and nanoconfinement effect, the resulting affinity towards SA is evidently enhanced with maximal adsorption capacity of 129.51 mg g−1 at neutral pH in the presence of H2O2. After five capture/release cycles, the adsorption capacity remains above 85 %. This proposed flower-shaped hierarchical micromotor expands the scope of potential materials for the adsorption of SA and provides a new and promising direction for fabricating adsorbents applied in the separation and purification of natural products.

Selective Hemin Binding by a Non‐G‐quadruplex Aptamer with Higher Affinity and Better Peroxidase‐like Activity

AbstractPrevious aptamers for porphyrins and metalloporphyrins were all guanine‐rich sequences that can fold in G‐quadruplex structures. Due to stacking‐based binding, these aptamers can hardly tell different porphyrins apart, and they can also bind other planar molecules, hindering their practical applications. In this work, we used the capture selection method to obtain aptamers for hemin and protoporphyrin IX (PPIX). The hemin aptamer (Hem1) features two highly conserved repeating binding loops, and it cannot form a G‐quadruplex, which was supported by its Mg2+‐dependent but K+‐independent hemin binding and CD spectroscopy. Isothermal titration calorimetry revealed much higher enthalpy change for the new aptamer, and the best aptamer showed a Kd of 43 nM hemin. Hem1 can also enhance the peroxidase‐like activity of hemin. This work demonstrates that aptamers have alternative ways to bind porphyrins allowing selective recognition of different porphyrins.

Selective Hemin Binding by a Non-G-quadruplex Aptamer with Higher Affinity and Better Peroxidase-like Activity.

Previous aptamers for porphyrins and metalloporphyrins were all guanine-rich sequences that can fold in G-quadruplex structures. Due to stacking-based binding, these aptamers can hardly tell different porphyrins apart, and they can also bind other planar molecules, hindering their practical applications. In this work, we used the capture selection method to obtain aptamers for hemin and protoporphyrin IX (PPIX). The hemin aptamer (Hem1) features two highly conserved repeating binding loops, and it cannot form a G-quadruplex, which was supported by its Mg2+ -dependent but K+ -independent hemin binding and CD spectroscopy. Isothermal titration calorimetry revealed much higher enthalpy change for the new aptamer, and the best aptamer showed a Kd of 43 nM hemin. Hem1 can also enhance the peroxidase-like activity of hemin. This work demonstrates that aptamers have alternative ways to bind porphyrins allowing selective recognition of different porphyrins.

Oncolytic herpes simplex viruses designed for targeted treatment of EGFR-bearing tumors

Oncolytic herpes simplex viruses (oHSVs) have emerged as leading cancer therapeutic agents. Effective oHSV virotherapy may ultimately require both intratumoral and systemic vector administration to target the primary tumor and distant metastases. An attractive approach to enhancing oHSV tumor specificity is engineering the virus envelope glycoproteins for selective recognition of and infection via tumor-specific cell surface proteins. We previously demonstrated that oHSVs could be retargeted to EGFR-expressing cells by the incorporation of a single-chain antibody (scFv) at the N terminus of glycoprotein D (gD). Here, we compared retargeted oHSVs generated by the insertion of scFv, affibody molecule, or VHH antibody ligands at different positions within the N terminus of gD. When compared to the scFv-directed oHSVs, VHH and affibody molecules mediated enhanced EGFR-specific tumor cell entry, spread and cell killing invitro, and enabled long-term tumor-specific virus replication following intravenous delivery invivo. Moreover, oHSVs retargeted via a VHH ligand reduced tumor growth upon intravenous injection and achieved complete tumor destruction after intratumoral injection. Systemic oHSV delivery is important for the treatment of metastatic disease, and our enhancements in targeted oHSV design are a critical step in creating an effective tumor-specific oHSVs for safe administration via the bloodstream.

Exploiting the Mechanical Bond Effect for Enhanced Molecular Recognition and Sensing.

The ubiquity of charged species in biological and industrial processes has resulted in ever-increasing interest in their selective recognition, detection, and environmental remediation. Building on the established coordination chemistry principles of the chelate and macrocyclic effects, and host preorganization, supramolecular chemists seek to construct specific 3D binding cavities reminiscent of biotic systems to enhance host-guest binding affinity and selectivity. Mechanically interlocked molecules (MIMs) present a wholly unique platform for synthetic host design, wherein topologies afforded by the mechanical bond enable the decoration of 3D cavities for non-covalent interactions with a range of target guest geometries. Notably, MIM host systems exhibit mechanical bond effect augmented affinities and selectivities for a variety of charged guest species, compared to non-interlocked acyclic and macrocycle host analogs. Furthermore, the modular nature of MIM synthesis facilitates incorporation of optical and electrochemical reporter groups, enabling fabrication of highly sensitive and specific molecular sensors. This review discusses the development of recognition and sensing MIMs, from the first reports in the late 20th century through to the present day, delineating how their topologically preorganized and dynamic host cavities enhance charged guest recognition and sensing, demonstrating the mechanical bond effect as a potent tool in future chemosensing materials.