Microchimica Acta最新文献

A first three-channel fluorescence probe (PVA) was designed and synthesized for the detection of peroxynitrite (ONOO⁻, 480–500 nm), viscosity (604 nm), and alcohol content (696–722 nm). Notably, the PVA exhibited the ability to co-localize the endoplasmic reticulum (ER), successfully detected the changes in ONOO⁻ in the endoplasmic reticulum (ER) of living cells (RAW 264.7 and HepG2 cells), as well as the fluctuations of ONOO⁻ levels triggered by acetaminophen (APAP). As a sensitive fluorescence probe, PVA was utilized to monitor viscosity changes induced by nystatin and rapamycin. As the viscosity increased, the twisted intramolecular charge transfer (TICT) in PVA was suppressed, resulting in a significant red fluorescence enhancement at 604 nm. Furthermore, PVA successfully tracked the process of endoplasmic reticulum autophagy (ER-phagy) under starvation conditions. Importantly, PVA demonstrated great potential for detecting alcohol content. Therefore, the development of a single fluorescent probe capable of three-channel sensing for ONOO⁻, viscosity, and ethanol content holds significant potential as a versatile tool in various fields, particularly in biological microenvironments, and industrial applications. PVA provides a conceptual framework for the rational design of future multifunctional probes.

Ensuring reliable detection in complex sample matrices remains a significant challenge. Dual-mode strategies offering built-in cross-validation present a promising solution. Herein, a miniaturized photoacoustic (PA)-photothermal (PT) dual-mode device was developed by integrating an origami paper-based platform and utilizing oxidized 3,3',5,5'-tetramethylbenzidine (oxTMB) as a signal probe. The CuS/g-C₃N₄ catalyzes the oxidation of colorless TMB into blue oxTMB, which generates strong PA and PT signals under 808 nm laser irradiation. Crucially, antioxidants (such as dopamine, ascorbic acid, and glutathione) inhibit the TMB oxidation, leading to a signal decrease. With a small sample volume of 15 μL and an analysis time of 30 min, the device demonstrated excellent stability, reproducibility, and accuracy. Its practical applicability was validated by the successful analysis of various real food samples. Overall, this work presents a novel dual-mode device that enables cross-validation and holds great potential for on-site food safety detection.

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The rational design of a photoactivated platinum–ferrocene-based metal–organic framework (Pt-Fc-MOF) biosensing platform is reported featuring triple-signal amplification for the rapid and visual detection of chloramphenicol (CAP) residues. The system combines aptamer-coated magnetic nanoparticles, cDNA-linked Pt-Fc-MOFs, and light-enhanced catalysis for triple-signal amplification. Upon specific target recognition, CAP binding induces aptamer conformational change, triggering the release of signal probes via nucleic acid strand displacement. The liberated Pt-Fc-MOFs incorporate ferrocene and platinum components that synergistically catalyze the oxidation of 3,3’,5,5’-tetramethylbenzidine (TMB) in the presence of H₂O₂, which is further enhanced upon light irradiation, generating an intensified colorimetric signal visible to the naked eye. This system demonstrates excellent sensitivity, with a remarkably low limit of detection (LOD) of 0.00016 ng·mL⁻¹, a wide linear detection range spanning from 0.0005 to 10 ng·mL⁻¹ and enables rapid, portable, and minimally instrumented detection. The incorporation of photoactivated catalysis offers a robust and portable strategy for real-time monitoring of foodborne antibiotics, advancing the development of next-generation MOF-based biosensors for point-of-care food safety diagnostics.

A visual and dual-targets detection platform for Staphylococcus aureus and Vibrio parahaemolyticus was established based on recombinant polymerase amplification (RPA), CRISPR/Cas12a and lateral flow test strip. The test strip was constructed using multicolored microspheres labeling antibody as tracer, and the results of detection of two kinds of bacteria could be displayed by different colored test lines on the test strip through the antigen-antibody specific recognition function, which realized results visualization and avoid cross-reaction. Due to the target-specific amplification of RPA and the sequence-specific recognition of Cas12a, the detection strategy could still show good sensitivity, specificity and accuracy in complex matrices. The visual limit of detection was as low as 50 CFU/mL, and the entire detection process could be completed within 42 min. In conclusion, a rapid and efficient detection platform for Staphylococcus aureus and Vibrio parahaemolyticus was developed, and this method is expected to provide a solution for the on-site detection of other foodborne pathogens in market and environmental food by simply changing the labeled antibody.

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A colorimetric platform was developed for hypoxanthine (HX) detection based on a biomimetic nanozyme, Hemin@BSA@ZIF-8, which was fabricated by conjugating hemin with bovine serum albumin (BSA) to enhance its stability, followed by encapsulation within a porous zeolitic imidazolate framework-8 (ZIF-8) structure. This hierarchical structure leveraged the synergistic effects resulting from the Hemin@BSA conjugation and ZIF-8’s porous confinement, yielding good catalytic performance. The morphology, elemental composition, and surface functional groups of Hemin@BSA@ZIF-8 were systematically characterized. HX was specifically oxidized by xanthine oxidase to generate an H₂O₂ intermediate, which subsequently catalyzed the oxidation of the 3,3’,5,5’-tetramethylbenzidine (TMB) to a blue product (oxidized TMB, TMB_− ox) by the Hemin@BSA@ZIF-8 complex. Under optimal conditions, HX was selectively and sensitively detected within a range 0-200 µM, with a detection limit of 17.05 µM. The proposed method was successfully applied to monitor the freshness of shrimp stored at 4 °C and 30 °C for varying durations. This work provides a robust, stable, and readily implementable strategy for food safety and environmental monitoring.

A functional fluorescent molecule, 4-bromo-1,8-naphthalimide derivative (BN1B) was designed and synthesized and used as a fluorescent probe for detecting Cr(VI) in aqueous media. The fluorescence intensity of BN1B decreased with increasing Cr(VI) concentration, and the detection limits were 3.64 × 10⁻⁶ mol·L^⁻1 for CrO₄^2⁻ and 2.98 × 10⁻⁶ mol·L^⁻1 for Cr₂O₇^2⁻. Moreover, a distinct fluorescence color change was observed for BN1B solutions containing CrO₄^2⁻ or Cr₂O₇^2⁻ under 356 nm UV irradiation, producing pale yellow and orange yellow emissions, respectively. The probe features simple preparation, low cost, fast response, and high sensitivity. Exploiting the favorable optical properties of BN1B, a supramolecular assembly, BN1B@Q[8], was constructed with cucurbit[8]uril (Q[8]). In this assembly, the benzene rings and part of the naphthalene moiety of BN1B are encapsulated by Q[8], forming a 2:1 host-guest inclusion complex. Furthermore, a film was prepared by incorporating BN1B@Q[8] into a polyvinyl alcohol (PVA) matrix at a mass ratio of 1:50. The film effectively isolated the assembly from atmospheric oxygen and moisture, suppressed non-radiative transitions, and induced long-lived room-temperature phosphorescence with a lifetime τ = 55.19 ms. The use of this phosphorescent film in anti-counterfeiting highlights its potential for expanding applications of luminescent materials in encryption and related fields.

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Hepatocellular carcinoma (HCC), accounting for 75–85% of liver cancers, faces limited therapeutic efficacy due to late-stage diagnosis, high malignancy, and poor drug permeability. Sorafenib (SF), a first-line multi-kinase inhibitor for unresectable HCC, suffers from low tumor-targeting efficiency and adverse effects. This study proposes a urease-driven nanomotor system (CUNMs + SF) to enhance SF delivery and tumor penetration. The nanomotors utilize porous magnetic silica nanoparticles (PMSNs) loaded with SF and modified with cyclodextrin-urease hybrids. This design enables magnetic targeting to HCC sites and autonomous propulsion via urea-fueled enzymatic conversion, overcoming physiological barriers in the tumor microenvironment.The system exhibits pH-responsive drug release (triggered at pH < 6.5) and induces ferroptosis in HCC cells by inhibiting the SLC7A13/GSH/GPX4 pathway, effectively suppressing tumor growth. In vitro and in vivo experiments demonstrate superior tumor accumulation, deep tissue penetration, and enhanced therapeutic outcomes compared to conventional SF. This work pioneers the application of enzyme-powered nanomotors in HCC therapy, addressing the limitations of systemic drug delivery while leveraging tumor-specific biochemical cues. The findings highlight the potential of biohybrid nanomotors for targeted cancer treatment and inspire future developments in stimuli-responsive nanomedicine for challenging malignancies.

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Cd(II) in electroplating wastewater can cause serious harm to the environment and human health. Although portable electrochemical equipment enables rapid on-site detection, the interference of Cu(II) affects the detection accuracy of Cd(II). To address this issue, we developed a novel sensor (SPE/UiO-66) with anti-Cu(II) interference properties and integrated it with portable electrochemical equipment. Experiments indicate that when both Cd(II) and Cu(II) concentrations are at 100 µg/L, the signal of Cd(II) on screen-printed electrode (SPE) is completely suppressed, whereas SPE/UiO-66 maintains 91% of the Cd(II) signal intensity. The SPE/UiO-66 exhibits excellent performance: a detection range of 50–200 µg/L and a limit of detection of 17 µg/L. Even if the electroplating wastewater contains a high concentration of Cu(II) (500 and 1000 µg/L), the recovery of Cd(II) after pretreatment with potassium ferricyanide can still reach 96% and 108%, respectively. The experiments and theory calculations revealed that UiO-66 enhances the adsorption capacity for Cu(II), causing Cu(II) to preferentially adsorb on UiO-66 rather than replace nearby Cd, thereby effectively alleviating the interference from Cu(II). This study provides a reliable portable electrochemical device for detecting Cd(II) in electroplating wastewater, which is of significant importance for environmental pollution prevention and control.

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MicroRNAs (miRNAs) are promising biomarkers for early cancer detection, but their low abundance and matrix interference continue to limit rapid, point-of-care (POC) assays. Here, we report a rapid, sensitive, and label-free biosensing platform for the detection of miRNA-133a-3p, a tumor-suppressive biomarker implicated in various cancers. The sensor operates on a non-faradaic capacitive principle, utilizing gold-plated printed-circuit-board interdigitated electrodes functionalized with thiolated single-stranded DNA capture probes. Alternating current electrokinetic (ACEK) effects are integrated with capacitive readout to achieve a single-step operation that enhances target transport to the interface, accelerates hybridization, and amplifies the capacitance transient. Assay conditions were optimized to achieve a linear dynamic range from 1 fM to 1 pM with a high sensitivity of 2.44%/min per decade and a limit of detection (LOD) as low as 0.56 fM in a standard buffer. High specificity was confirmed through selectivity tests against non-complementary miRNAs. For serum analysis, only a simple 1:100 dilution is required prior to measurement, yielding a LOD of 0.74 fM in diluted serum (equivalent to 74 fM in neat serum). This portable and cost-effective ACEK-capacitive platform enables fast and selective miRNA detection in complex matrices with minimal sample preparation.

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