Microchimica Acta最新文献

Acetone in human exhaled breath is a key biomarker for diabetes, yet current metal oxide-based acetone sensors face challenges in detecting low-concentration acetone effectively at room temperature. Herein, we report a heterojunction by self-assembled peptide fibrillar nanoforests (SPNFs) and ZnO to fabricate an acetone sensor device. Among these materials, the well-ordered and uniformly arranged SPNFs offer a large surface area and a porous framework that promotes target gas adsorption, while also facilitating the homogeneous distribution of ZnO nanoparticles. Under room temperature and UV illumination, the SPNFs/ZnO-3 sensor demonstrates a response of 5.86 to 50 ppm acetone—over fourfold higher than that of pure ZnO. Furthermore, this sensor features a low detection limit and exhibits a response of 1.59 in the presence of 1 ppm acetone. The proposed methodology establishes a novel platform for the design and fabrication of gas sensors applicable to life health, environmental surveillance, and other fields, with excellent compatibility with existing microelectronic technology processes.

Graphical abstract

Real-time monitoring of lipid droplets (LDs) dynamics is critical for elucidating lipid metabolic pathways enabling early diagnosis of related diseases. In this study, we developed three novel donor-acceptor (D-π-A) type aggregation-induced emission (AIE) near-infrared (NIR) fluorescent probes, namely TPA-T1, TPA-T2, and TPA-T3. Among them, TPA-T2 exhibited the most pronounced fluorescence enhancement and excellent lipophilicity, enabling real-time visualization of LDs fluctuations in living cells. Experimental results demonstrated that TPA-T2 not only effectively tracked LDs dynamics but also revealed the functional involvement of LDs in cell death pathways such as ferroptosis and cuproptosis. Furthermore, TPA-T2 displayed a high degree of sensitivity to drug-induced metabolic changes, effectively distinguish normal liver tissue from fatty liver tissue, offering a valuable tool for pharmacodynamic assessment and early diagnosis of lipid metabolism-related diseases. When applied to tumor models, TPA-T2 was able to selectively label LDs within tumor tissues, underscoring its potential for studying tumor metabolic phenotypes. Overall, this work provides a novel molecular imaging tool for elucidating the mechanisms of metabolic diseases and offers broad application prospects in lipid metabolism research, cancer biology, and disease diagnostics.

This work is framed within the paradigm of Circular Analytical Chemistry (CAC), which promotes the integration of waste-derived materials, minimization of resource consumption, and development of near closed-loop analytical procedures. In line with this prevailing trend, we present a proof-of-concept extraction device constructed entirely from LEGO^® bricks, serving as supports for a thin coating composed of carboxylated multi-walled carbon nanotubes dispersed in L-menthol (1.3% w/w). The proposed tool combines a modular and reusable plastic support, with a sorptive phase derived from renewable and low-impact components. The extraction procedure was applied to the extraction of eight common pesticides from tap water samples thanks to the adsorption properties of the coating layer, solid at room temperature; after the adsorption, the analyte was recovered employing the thermo-responsive properties of the sorbent, by placing the brick in a beaker and heating at 60 °C to melt menthol. The extract was diluted with isopropanol and directly injected in the UPLC-DAD/MS system. The workflow is nearly zero-waste, requiring only 200 µL of isopropanol to wash the brick and avoid solidification of the menthol extract, which can be directly injected for the chromatographic analysis after centrifugation. Besides its sustainable design, the method demonstrates good analytical performance, with average recoveries ranging from 86.6 to 113%, precision between 2.7 and 15%, and limits of quantification ≤ 0.15 µg L^− 1, comparable or even better than conventional extraction techniques. Besides analytical performance, this approach embraces the concepts of recycling, moving beyond the traditional approaches of Green Analytical Chemistry toward strategies that valorise waste materials and pursue the broader goals of CAC.

Graphical abstract

Thrombotic diseases remain a major global health concern with high morbidity and mortality. Four biomarkers (TAT, t-PAIC, TM, PIC) enable real-time monitoring of coagulation, addressing limitations of traditional diagnostics. Herein, we developed a multiplex electrochemical immunosensor for the simultaneous detection of these biomarkers. The sensing platform is constructed on a glassy carbon electrode modified with gold nanoparticles and laser-induced graphene (AuNPs-LIG), which enhances conductivity and signal output. A “One-for-Four” strategy was employed using four distinct redox probes (AQ, OAP, MB, PPD), each conjugated to a specific antibody via amidation and anchored to functionalized carbon nanotubes (Au@CNTs), forming a multichannel signal amplification system with high sensitivity. The immunosensor exhibited excellent linearity (10–100 ng/mL, R² > 0.98) and low detection limits: 3.99 ng/mL (TAT), 5.25 ng/mL (t-PAIC), 2.51 ng/mL (TM), and 4.20 ng/mL (PIC). It also demonstrated high selectivity, reproducibility and long-term stability. Recovery in human plasma ranged from 84.1% to 112.21%, indicating strong applicability to complex clinical samples. This work presents a robust, portable POCT platform with great potential for early diagnosis and dynamic monitoring of thrombotic diseases.

Graphical Abstract

Abscisic acid (ABA) is a key phytohormone that regulates plant responses to abiotic stresses such as drought, salinity, and cold, serving as an important biomarker for plant health. Traditional ABA detection methods, primarily chromatographic and immunoassay-based, are invasive, labor-intensive, and unsuitable for continuous monitoring in natural growth conditions. Wearable sensors offer a promising solution for in situ, non-destructive, and real-time monitoring of plant stress responses. This manuscript highlights the advantages of electrochemical sensing platforms over physical and electrophysiological modalities for direct hormone detection. Moreover, this manuscript discusses material considerations, including biocompatibility, molecular specificity, mechanical flexibility, and environmental resilience, which are critical for reliable field deployment. Recent advances in molecularly imprinted polymers, hydrogel-based interfaces, and nanomaterial composites such as graphene and carbon nanotubes are evaluated for their potential to enhance sensitivity and selectivity. Challenges, including sensor stability, interference from complex plant matrices, and integration with low-power electronics, are also addressed. Continuous, real-time data from wearable sensors provides a dynamic view of plant stress, surpassing conventional snapshot measurements. Furthermore, advances in flexible electronics and miniaturization enable seamless integration with plant tissues without causing damage. Finally, this manuscript focuses on future research directions on hybrid sensor design, wireless communication, and AI-driven analytics to enable high-resolution monitoring of plant stress (ABA). Wearable electrochemical sensors thus hold transformative potential for precision agriculture, supporting proactive crop management and sustainable farming practices.

Graphical abstract

The practical applications of lightweight high-entropy alloys (HEAs) in catalysis and electrochemical sensors are hindered by inadequate chemical stability and catalytic activity. This study presents one groundbreaking synthesis strategy for fabricating Mg_0.3AlVCuZn HEA nanoparticles by integrating histidine/serine-functionalized boron-doped graphene quantum dot (HSB-GQD). Mg²⁺, Al³⁺, V⁵⁺, Cu²⁺ and Zn²⁺ are coordinated with HSB-GQD to Me-HSB-GQD complex,followed by thermal annealing and controlled oxidative post-treatment. The resulting Mg_0.3AlVCuZn shows single-phase octahedral morphology with a small size of about 50 nm and dual graphene-oxide shielding. Unique structure fully exposes active sites and enhances structural and chemical stability across acidic/alkaline media, interface electron transfer, and improves the affinity with polar electrolyte. The s-p-d orbital hybridization among Mg/Al (s, p) and V/Cu/Zn (s, d) induces electron redistribution to optimize adsorption energetics and catalytic specificity. Mg_0.3AlVCuZn shows ultrahigh catalytic activity that is more than 2-fold that of Au nanoparticles. The electrochemical sensor with Mg_0.3AlVCuZn exhibits a broad linear range (0.01–100 µM), ultra-low detection limit (0.0057 µM, S/N = 3), and robust selectivity and long-term stability for electrochemical detection of doxorubicin in human urine. This study also offers a generalizable platform for engineering lightweight HEAs with tailored stability and multifunctional efficacy, bridging advances in catalysis, sensing and energy storage.

Electrochemiluminescent (ECL) luminophore with high quantum efficiency is one of the most essential components in ECL biosensor system. However, high excitation potential caused oxygen emission in electrolyte damages the modified electrode and biological activity, which limits the efficiency of luminophores. Herein, perylene-3,4,9,10-tetracarboxylic acid (PTC) was employed as an organic ligand to synthesize a perylene derivative nanosheet (PDIP) which was characterized by a significantly lower excitation potential of -0.28 V and a narrow potential sweep range (-0.3 V–0.3 V). Silver nanoparticle-functionalized PDIP (Ag@PDIP) was further synthesized and applied to construct an ECL biosensor system (Ag@PDIP/GCE/K₂S₂O₈). Ag@PDIP possessed a more positive excitation potential (-0.21 V) and a 1.8-fold enhancement in quantum efficiency compared to PDIP. The sensitivity and specificity of Ag@PDIP/GCE/K₂S₂O₈ were testified in detecting programmed death ligand 1 (PD-L1), achieving a five-order linear dynamic range (100 fg/mL–100 ng/mL), along with a remarkably low detection threshold of 10 fg/mL, and high selectivity towards PD-L1. The newly synthesized PDIP showed significant enhancement in quantum efficiency of ECL luminophore, and its successful application in detecting PD-L1 provided a prospective and efficient approach for ECL-based clinical detection of biomarkers.

Graphical abstract

Gallium (Ga)-based liquid metals (LM) exhibit high antimicrobial efficacy due to their ability to release Ga³⁺ in situ, which can effectively inhibit the growth of a wide range of bacteria. In this study, a novel photothermal antimicrobial material, MXene@LM, was synthesized via simple electrostatic interactions for the detection and management of methicillin-resistant Staphylococcus aureus (MRSA). The incorporation of LM not only enhances the local electric field strength and promotes electron transfer on the surface of MXene but also significantly improves the light absorption and photothermal conversion efficiencies of MXene. Consequently, the photothermal antimicrobial properties of MXene@LM are greatly enhanced. Additionally, Ga³⁺ released by LM disrupts bacterial iron metabolism and leads to bacterial death. An electrochemical sensor for the detection of MRSA was successfully constructed based on MXene@LM with an LOD of 949 CFU/mL and applied to a variety of aqueous environments. This study lays an important scientific foundation for the design of novel photothermal antimicrobial materials and shows promising applications in real environments.

Graphical abstract

Staphylococcus aureus (S. aureus) is a versatile pathogen responsible for a wide range of illnesses from minor skin infections to critical conditions like pneumonia, sepsis, and toxic shock syndrome in humans. Clumping factor A (ClfA), a surface protein of S. aureus, plays a crucial role in bloodstream infections by attaching to fibrinogen, facilitating bacterial adherence and clumping. This study describes the selection of DNA aptamers, specific to ClfA using the technique of Ni-NTA affinity systematic evolution of ligands by exponential enrichment (SELEX). A DNA library of 76-mer single-stranded oligodeoxynucleotides with a 40-mer random region was utilized. The SELEX process involved thermal equilibration, incubation with ClfA immobilized on Ni-NTA beads, and multiple washing and elution steps. Oligonucleotide pool obtained from the final round was cloned and sequenced. Selected aptamers were validated using microtiter plate-based aptamer binding assay, molecular docking, electrophoretic mobility shift assay (EMSA), and bead-based binding assay. The aptamer (CA 11.1) binding affinity was determined by nonlinear regression analysis, yielding an apparent dissociation constant (K_D) of 264 nM. The aptamer and ClfA binding interactions were predicted using HDOCK. The selected aptamer displayed specificity for S. aureus, by showing four times higher binding for the target as compared to non-target bacteria. CA 11.1 exhibited S. aureus binding in a linear range of 10³ to 10⁸ CFU/mL and a limit of detection (LOD) of 10³ CFU/mL, determined using graphene oxide (GO) platform. The analytical performance of the selected aptamer was tested in food (milk) and human serum samples spiked with S. aureus, demonstrating its suitability for real sample analysis. This study highlights the effectiveness of aptamer-based bio-receptors in detecting S. aureus, offering a promising approach for diagnostic and therapeutic applications.

Graphical abstract

A novel analytical method is proposed that integrates monolithic sorbent micro-solid-phase extraction (µ-SPE) with an anodized screen-printed graphene electrode for the determination of serotonin (SER). Monolithic sorbent µ-SPE offers a straightforward and efficient pretreatment method for removing of interfering substances, thereby enhancing the selectivity of SER analysis before being coupled with an electrochemical sensor. Under optimal conditions, the integration of monolithic sorbent µ-SPE with the electrochemical sensor provided a broad linear range of 50–1500 nM for SER detection, with detection and quantification limits of 4.78 and 15.94 nM, respectively. The developed sensor exhibited excellent reproducibility (RSD < 10%) and good stability over a period of 6 months. Furthermore, the proposed method can detect SER even in the presence of ascorbic acid and uric acid at their normal levels in human biological fluids. This method was successfully applied to determine SER levels in real urine samples with an acceptable recovery range of 93.76%–124.14%. The analytical results derived from the developed methodology are strongly correlated with those obtained using the standard high-performance liquid chromatography method.

Graphical Abstract