Search Results (105)

The global surge in illicit drug use has intensified the demand for rapid, portable, and reliable on-site detection technologies. Traditional analytical approaches, such as laboratory-based instrumentation and biological sample assays, while accurate, are often constrained by high costs, long processing times, and the need for specialized equipment, rendering them unsuitable for field applications. This review highlights recent progress in chemical sensor technologies designed for the detection of widely misused drugs such as methamphetamine, cocaine, fentanyl, and heroin. Parallel advancements in the detection of environmental contaminants, particularly concerning micro- and nanoplastics, are also discussed. Emerging sensing platforms employing nanoparticle functionalization, graphene nanosheets, MXenes, metal–organic frameworks (MOFs), and supramolecular colorimetric assays demonstrate significant potential for achieving high sensitivity, selectivity, and operational simplicity in portable formats. These innovations enable real-time detection with minimal user expertise, thereby advancing applications in forensic analysis, environmental monitoring, and public health protection. The review also addresses current limitations related to detection accuracy, reagent stability, and matrix interferences and proposes future directions for optimizing sensor robustness and performance under diverse field conditions. Full article

The incorporation of carbon nanostructures into polymer composites is of significant importance for the development of novel sensor materials, due to the excellent mechanical strength and variable electrical conductivity that these structures provide. It is evident that the significance of polylactide (PLA) and carbon nanotube (CNT) systems is attributable to two key factors. Firstly, these systems are notable for their environmental sustainability. Secondly, they exhibit enhanced functional properties. Despite the fact that a considerable number of studies have been conducted on conductive PLA/CNT composites, there has been limited research focusing on the supramolecular ordering of the polymer matrix and its impact on electromechanical properties. This factor, however, has been demonstrated in this study to significantly influence their response to applied stress and, consequently, their potential application as stress sensors. The present study has demonstrated that the precipitation method is an effective means of producing conductive PLA/MWNTs nanocomposites. This method is effective in ensuring the uniform dispersion of the filler in the polymer matrix, which creates an interesting prospect for mechanical sensors. It is evident that the durability of the nanocomposites is a key factor in ensuring the ordering of the supramolecular structure of the PLA matrix into the α form. The materials obtained were found to have a low percolation threshold of 0.2 wt.%. Furthermore, the practical application of these sensors, in the form of resistive strain sensors, was demonstrated for materials containing 5 wt.% of carbon nanotubes. The results presented here demonstrate that this methodology provides a novel perspective on the production of sensor materials, with the supramolecular ordering of the PLA matrix being a key factor. Full article

The scientific community has been interested in lophine’s versatility and usage in various applications. Research has shown that humic acid is a material that exhibits interference with lophine. Humic molecules associate with each other in supramolecular conformations through weak hydrophobic interactions at alkaline or neutral pH and hydrogen bonds at low pH. This work presents the characterization of a sensitive lophine layer based on water’s hydrogen ions (pH). We conducted a spectroscopy study to analyze how the absorbance at different amounts of lophine depends on pH. This study demonstrates the hyperchromic behavior of imidazole at various pH values, which may be utilized in an intrinsic fiber optic pH sensor. The dynamic range of the fiber optic sensor was 5 to 11.3 pH units. The sensor was developed by coating a thinned fiber with a sensitive lophine layer. It achieves a sensitivity of 0.27 dB/pH and a response time of 5 s. Full article

Tubular aggregate myopathy (TAM) is an inherited skeletal muscle disease associated with progressive muscle weakness, cramps, and myalgia. Tubular aggregates (TAs) are regular arrays of highly ordered and densely packed straight-tubules observed in muscle biopsies; the extensive presence of TAs represent a key histopathological hallmark of this disease in TAM patients. TAM is caused by gain-of-function mutations in proteins that coordinate store-operated Ca²⁺ entry (SOCE): STIM1 Ca²⁺ sensor proteins in the sarcoplasmic reticulum (SR) and Ca²⁺-permeable ORAI1 channels in the surface membrane. Here, we assessed the therapeutic potential of endurance exercise in the form of voluntary wheel running (VWR) in mitigating TAs and muscle weakness in Orai1^G100S/+ (GS) mice harboring a gain-of-function mutation in the ORAI1 pore. Six months of VWR exercise significantly increased specific force production, upregulated biosynthetic and protein translation pathways, and normalized both mitochondrial protein expression and morphology in the soleus of GS mice. VWR also restored Ca²⁺ store content, reduced the incidence of TAs, and normalized pathways involving the formation of supramolecular complexes in fast twitch muscles of GS mice. In summary, sustained voluntary endurance exercise improved multiple skeletal muscle phenotypes observed in the GS mouse model of TAM. Full article

A polyoxometalate-based metal–organic complex with the ability to treat pollutants in water was obtained under hydrothermal conditions, namely [Ni(H₂L)(HL)₂](PMo₁₂O₄₀)·3H₃O·4H₂O (1) (H₂L = 4,4′-(1H,1′H-[2,2′-biimidazole]-1,1′-diyl)dibenzoicacid). Structural analysis reveals that the [Ni(H₂L)(HL)₂] units are interconnected into a 2D layer via hydrogen bonds between adjacent carboxyl groups and water molecules of crystallization. [PMo₁₂O₄₀]³⁻ anions are embedded within the larger pores of the layer and are connected to the adjacent layers through hydrogen bonds, ultimately expanding the structure into a 3D supramolecular architecture. The intermolecular interactions were studied via Hirshfeld surface (HS) analysis. Electrochemical performance tests reveal that 1 exhibits electrocatalytic activity toward the oxidation and reduction of diverse pollutants in water, including NO₂⁻, Cr(VI), BrO₃⁻, Fe(III), and ascorbic acid (AA). Additionally, it can also serve as an amperometric sensor for the detection of BrO₃⁻ and Cr(VI). Photocatalytic studies reveal that compound 1 functions as a bifunctional photocatalyst, which not only achieves efficient degradation of organic dyes but also demonstrates remarkable reduction efficiency for toxic Cr(VI). Compound 1 demonstrates significant potential for practical water remediation applications. Full article

A chiral gelator (R)-H₆L with multiple carboxyl groups based on a 1,1′-bi-2,2′-naphthol (BINOL) skeleton was prepared, and it could form a supramolecular gel under the induction of water in DMSO/H₂O and DMF/H₂O (1/1, v/v). In the EtOH/H₂O system, the original partial gel transformed into a stable metal–organic gel (MOG), specifically with Cu²⁺ among 20 metal ions. It is proposed that Cu²⁺ coordinates with the carboxyl groups of (R)-H₆L to form a three-dimensional network structure. With the addition of a variety of α-hydroxy acids and amino acids, the Cu²⁺-MOG collapsed with merely 0.06 equivalents of L-tartaric acid (L-TA), while other acids required much larger amounts to achieve the same effect, realizing the visual chemoselective and enantioselective recognition of tartaric acid. Therefore, the chiral gelator (R)-H₆L achieved the tandem visual recognition of Cu²⁺ and chiral tartaric acid by sequence gel formation and collapse, offering valuable insights for visual sensing applications and serving as a promising model for future chiral sensor design. Full article

Supramolecular chemistry relies on the dynamic association/dissociation of molecules through non-covalent interactions. These interactions of a self-assembled system can be strategically exploited for sensing several microorganisms. Moreover, supramolecular systems can also be combined with other functional components like nanoparticles, self-assembled monolayers, and microarray systems to produce multicomponent sensors with higher sensitivity and lower detection time. In this review, we will discuss how cutting-edge supramolecular chemistry has enabled scientists to develop microbial biosensors with high reliability and rapid detection time. Moreover, they produce high-throughput operations, real-time monitoring, extensive operation platforms, and cost-effective production. This review can serve as a conceptual background for understanding state-of-the-art rapid detection methods of microbial biosensing. Full article

This study investigates the effect of polyvinylidene fluoride–CoFe₂O₄ (PVDF-CFO) composite film thickness on their supramolecular structure, phase composition, and dielectric properties. The composites were synthesized from PVDF with CFO nanoparticles using the Dr. Blade method to obtain film thicknesses ranging from 15 to 58 μm. The data obtained show that the thinner film (15 μm) has a higher β-phase content compared to the thicker films (58 μm), as confirmed by FTIR and Raman spectroscopy. Scanning electron microscopy (SEM) showed that increasing film thickness within the studied range leads to the development of larger spherulitic structures and increased porosity. Atomic force microscopy (AFM) analysis also showed that thicker films have higher tensile strength due to their larger cross-sectional area, while thinner films exhibit lower elasticity. A more uniform microstructure and an increased electroactive phase in thin films result in increased permittivity, which is critical for PVDF-based sensors and energy devices. Full article

Enzyme-based portable amperometric biosensors are precise and low-cost medical devices used for rapid cancer biomarker screening. Sarcosine (Sar) is an ideal biomarker for prostate cancer (PCa). Because human serum and urine contain complex interfering substances that can directly oxidize at the electrode surface, rapid Sar screening biosensors are relatively challenging and have rarely been reported. Therefore, highly sensitive and selective amperometric biosensors that enable real-time measurements within <1.0 min are needed. To achieve this, a chitosan–polyaniline polymer nanocomposite (CS–PANI NC), a carrier for dispersing mesoporous carbon (MC), was synthesized and modified on a screen-printed carbon electrode (SPCE) to detect hydrogen peroxide (H₂O₂). The sarcosine oxidase (SOx) enzyme-immobilized CS–PANI–MC-2 ternary NCs were referred to as supramolecular architectures (SMAs). The excellent electron transfer ability of the SMA-modified SPCE (SMA/SPCE) sensor enabled highly sensitive H₂O₂ detection for immediate trace Sar biomarker detection. Therefore, the system included an SMA/SPCE coupled to a portable potentiostat linked to a smartphone for data acquisition. The high catalytic activity, porous architecture, and sufficient biocompatibility of CS–PANI–MC ternary NCs enabled bioactivity retention and immobilized SOx stability. The fabricated biosensor exhibited a detection limit of 0.077 μM and sensitivity of 8.09 μA mM⁻¹ cm⁻² toward Sar, demonstrating great potential for use in rapid PCa screening. Full article

Recently, 4-(pyrrol-1-yl)pyridine has been found to act as a supramolecular chemodosimeter, sensing nitrite ions in an aqueous solution with naked eye detection and a low limit of detection of 0.330 ppm. This work explores the anion-sensing properties of related derivatives, 4-(2,5-dimethyl-pyrrol-1-yl)pyridine and 4-(2,4-dimethyl-pyrrol-1-yl)pyridine, and provides a comparison with the parent compound. These molecules are determined to be effective sensors for nitrite ions with limits of detection of 1.06 ppm and 1.05 ppm, respectively. The high sensitivity and selectivity to nitrite remain even in the presence of competing anions such as SO₃²⁻, NO₃²⁻, PO₄³⁻, SO₄²⁻, Cl⁻, F⁻, I⁻, Br⁻, AcO⁻, and CN⁻. Analogous to the 4-(pyrrol-1-yl)pyridine system, the sensing mechanism appears to be the result of changes in the supramolecular aggregate system upon the interaction of an anion; this is further explored through dynamic light scattering, the Tyndall effect, and NMR spectroscopy. The two methylated derivative systems reported herein, 4-(2,5-dimethyl-pyrrol-1-yl)pyridine and 4-(2,4-dimethyl-pyrrol-1-yl)pyridine, are shown to affect the size of the supramolecular system and provide further insight into the unique mechanism of action. Full article

Pesticide residues pose significant risks to human health and the environment, emphasizing the need for sensitive detection and analysis methods. Fluorescence-based sensors, particularly those utilizing aggregation-induced emission (AIE) fluorophores (AIEgens), have demonstrated exceptional performance in this area. This review summarizes key advancements in pesticide detection sensors based on AIEgens, detailing their luminescence mechanisms and fluorescence sensing principles. It explores various applications of AIEgens in fluorescence sensors, including organic small-molecule sensors, nanocomposite sensors, metal-organic framework sensors, supramolecular sensors, fluorescent porous organic polymer sensors, and lateral flow immunoassay sensors, with specific examples illustrating their detection mechanisms and performance. This review also discusses current challenges and future perspectives for the development of these sensors. We anticipate that this review will serve as a valuable and timely resource for researchers working to advance the development and application of AIEgens-based sensors in pesticide detection. Full article

Triazine pesticide (atrazine and its derivatives) detection sensors have been developed to thoroughly check for the presence of these chemicals and ultimately prevent their exposure to humans. Sensitive coatings were designed by utilizing molecular imprinting technology, which aims to create artificial receptors for the detection of chlorotriazine pesticides with gravimetric transducers. Initially, imprinted polymers were developed, using acrylate and methacrylate monomers containing hydrophilic and hydrophobic side chains, specifically for atrazine, which shares a basic heterocyclic triazine structure with its structural analogs. By adjusting the ratio of the acid to the cross-linker and introducing acrylate ester as a copolymer, optimal non-covalent interactions were achieved with the hydrophobic core of triazine molecules and their amino groups. A maximum sensor response of 546 Hz (frequency shift/layer height equal to 87.36) was observed for a sensitive coating composed of 46% methacrylic acid and 54% ethylene glycol dimethacrylate, with a demonstrated layer height of 250 nm (6.25 kHz). The molecularly imprinted copolymer demonstrated fully reversible sensor responses, not only for atrazine but also for its metabolites, like des-ethyl atrazine, and structural analogs, such as propazine and terbuthylazine. The efficiency of modified molecularly imprinted polymers for targeted analytes was tested by combining them with a universally applicable quartz crystal microbalance transducer. The stable selectivity pattern of the developed sensor provides an excellent basis for a pattern recognition procedure. Full article

In the periodic table of the elements, ruthenium occupies an excellent position, just below iron. And like iron, it possesses several oxidation states, with +2 and +3 being the most common. Accordingly, ruthenium chemistry is extremely rich and well developed, and ruthenium complexes show excellent catalytic aptitude, tremendous redox capacity, and intriguing biological activity. However, in the design of sensors, the use of ruthenium complexes can be better exploited, as they possess valuable electro- and photochemical properties. Therefore, there is an opportunity here, and ruthenium-based complexes might become, one day, key players in sensing technology. Starting a new research project with ruthenium-based sensors ourselves, writing this review was essential to see the current state of research in the field, to better identify opportunities and to have an overview of state-of-the-art examples. Full article

Supramolecular chemistry is a relatively new field of study that utilizes conventional chemical knowledge to produce new edges of smart materials. One such material use of supramolecular chemistry is the development of sensing platforms. Biologically relevant molecules need frequent assessment both qualitatively and quantitatively to explore several biological processes. In this review, we have discussed supramolecular sensing techniques with key examples of sensing several kinds of bio-analytes and tried to cast light on how molecular design can help in making smart materials. Moreover, how these smart materials have been finally used as sensing platforms has been discussed as well. Several useful spectroscopic, microscopic, visible, and electronic outcomes of sensor materials have been discussed, with a special emphasis on device-based applications. This kind of comprehensive discussion is necessary to widen the scope of sensing technology. Full article

A comprehensive study was performed on the supramolecular ordering and optical properties of thin nanostructured glycerohydrogel sol-gel plates based on chitosan L- and D-aspartate and their individual components in the X-ray, UV, visible, and IR ranges. Our comparative analysis of chiroptical characteristics, optical collimated transmittance, the average cosine of the scattering angle, microrelief and surface asymmetry, and the level of structuring shows a significant influence of the wavelength range of electromagnetic radiation and the enantiomeric form of aspartic acid on the functional characteristics of the sol-gel materials. At the macrolevel of the supramolecular organization, a complex topography of the surface layer and a dense amorphous–crystalline ordering of polymeric substances were revealed, while at the nanolevel, there were two forms of voluminous scattering domains: nanospheres with diameters of 60–120 nm (L-) and 45–55 nm (D-), anisometric particles of lengths within ~100–160 (L-) and ~85–125 nm (D-), and widths within ~10–20 (L-) and ~20–30 nm (D-). The effect of optical clearing on glass coated with a thin layer of chitosan L-(D-)aspartate in the near-UV region was discovered (observed for the first time for chitosan-based materials). The resulting nanocomposite shape-stable glycerohydrogels seem promising for sensorics and photonics. Full article