Multi-mycotoxin detection is extremely important for preventing their great harm to human health. Here, a zeolitic imidazolate framework-8 (ZIF-8) with adsorbing nitrogen-doped carbon dots (N-CDs) and DNA tetrahedron nanostructures (DTNs) bipolar nanoprobe-driven electrochemiluminescence (ECL) aptasensor was proposed for the co-detection of aflatoxin B1 (AFB1) and zearalenone (ZEN). A pair of N-CDs, namely N-CDs1 and N-CDs2, with distinguishable emission potentials, was designed as the cathode and anode luminophores. The positively charged ZIF-8, which has a large specific surface area and a porous structure, was able to load abundant negatively charged N-CDs1 and N-CDs2, resulting in greatly improved sensitivity. The amino-terminated AFB1-specific aptamer (Apt1) and ZEN-specific aptamer (Apt2) were covalently coupled to N-CDs1/ZIF-8 and N-CDs2/ZIF-8 to serve as the signal probes for AFB1 and ZEN, respectively. The rationally designed DTNs were firmly immobilized onto the sensing face of the gold electrode (AuE), forming a pyramid-like scaffold for the Apt1/N-CDs1/ZIF-8 and Apt2/N-CDs2/ZIF-8 probes, endowing the aptasensing platform with outstanding stability and rigidity. The competitive recognition of AFB1 and/or ZEN with Apt1 and/or Apt2 triggered the detachment of signal probes from the AuE surface, leading to remarkably decreased ECL intensity of N-CDs1 or/and N-CDs2. Under optimal conditions, the as-fabricated ECL aptasensor exhibited high sensitivity, with limits of detection (LODs) as low as 3.3 pg/mL, and a broad linear range of 0.01–1,000 ng/mL for both AFB1 and ZEN. It also succeeded in nine batches of Coix seed samples. The novel N-CDs/ZIF-8 and DTNs nanoprobe-driven pyramid-shaped ECL aptasensing platform displays considerable promise for on-site co-detection of multi-mycotoxins and other hazards by simply modifying the corresponding aptamers.
To address the current challenges associated with microporous organic networks (MONs) for high-performance liquid chromatography (HPLC), such as high backpressure and reduced column efficiency caused by direct packing of irregular nano- or submicron-sized MON particles, as well as limited separation performance due to MON aggregation and inhomogeneous distribution in conventional physically doped MON-based monolithic columns, this work proposes an innovative post-modification strategy to fabricate vinyl-functionalized MON (vinyl-MON) bonded monolithic column to enhance the HPLC performance of small molecules. Such a chemical bonding method ensures uniform dispersion of OH-MON within the polymer matrix and improves structural stability. Compared with physically doped OH-MON monolithic columns, bare monolithic columns, and a commercial C18 column, the vinyl-MON bonded monolithic column exhibits superior chromatographic performance in separating neutral, acidic, and basic small-molecule organic compounds. Tanaka tests and density functional theory (DFT) calculations indicate multiple interactions between the vinyl-MON bonded monolithic column and target compounds, including hydrogen bonding, π–π interactions, and hydrophobic interactions. Furthermore, this monolithic column can be used for analyzing parabens in environmental water samples. This work not only provides a new strategy for engineering novel MON-based monolithic columns, but also indicates the prospect of MON-based monolithic columns in HPLC.
Fungal keratitis, a severe infectious corneal disease, could lead to vision loss due to its uncontrolled progression and corneal damage. Current standard antifungal eye drops often fail in treatment, primarily due to poor ocular bioavailability from rapid tear clearance and limited corneal penetration. In this work, we developed a dual-drug-loaded microneedle (MN) patch featuring rapid effervescent detachment for targeted treatment of fungal keratitis. This MN patch comprises a methacrylated hyaluronic acid (MeHA) needle tip encapsulating amphotericin B (AmB), an effervescent middle layer loaded with voriconazole (VCZ) and poly(vinyl pyrrolidone) (PVP), and a supportive polystyrene (PS) backing, termed the MeHA-PVP-PS MN patch. When the MeHA-PVP-PS MN patch was inserted into the cornea, the effervescent reaction enabled the needle tips to detach rapidly within 15 s, which could minimize the contact time between the needle and the cornea. In vitro drug release tests, assessed via absorbance assays, revealed high drug loadings of AmB (52.98 ± 3.62 µg) and VCZ (198.54 ± 5.13 µg) in phosphate-buffered saline and anhydrous ethanol, respectively. In vivo rabbit pharmacokinetics analysis revealed elevated drug levels in the cornea and aqueous humor, with VCZ levels increased by more than 3-fold and AmB levels nearly doubled compared to conventional eye drops. In fungal keratitis rabbit models, eyes treated with MeHA-PVP-PS MN patch showed reduced inflammation, faster epithelial recovery, and lower clinical scores than the control group. Overall, the MeHA-PVP-PS MN patch enables rapid, minimally invasive dual-drug delivery, demonstrating the potential of microneedle-mediated intrastromal drug delivery for fungal keratitis treatment.
Cancer is a global concern due to the severity of the disease and the increase in the number of patients over the years. The identification of specific circulating biomarkers (mostly proteins with aberrant glycosylation patterns) and their reliable screening (liquid biopsy) is of great importance for early disease diagnosis and monitoring disease stability or cancer progression. Molecularly imprinted polymers (MIPs) are artificial receptors with the capability of recognizing the desired clinical biomarkers in human biofluids. Their integration with photonic methods, such as surface plasmon resonance (SPR), surface-enhanced Raman spectroscopy (SERS), and fluorescence, provides a promising approach for selective, sensitive, and cost-effective screening of cancer. This review highlights the most impactful state-of-the-art research works, followed by a discussion of the key challenges and limitations of MIP-based photonic devices (e.g., template removal, reproducibility, scalability). In the end, future improvements and innovation pathways for this sensing technology are discussed along with the main conclusions of the literature review.
This research describes the application of a highly sensitive and selective differential pulse voltammetric method for the determination of Cu(II) in various environmental and food samples based on the oxidation/reduction of the Cu(II)-bisneocuproine complex ([Cu(NC)2]2+) at a Nafion-coated pencil graphite electrode (Nf@PGE). Differential pulse voltammetric measurements indicated that the proposed platform provided three linear ranges for both the oxidation (1.0–10.0, 10.0–100.0, and 102–104 nM) and reduction (1.0–10.0, 10.0–75.0, and 75.0–104 nM) of [Cu(NC)2]2+. Oxidation and reduction of the complex at the Nf@PGE yielded high sensitivity values of 1.28 and 4.60 µA/(µM·cm2), along with lower limit of detection (LOD) values of 0.33 and 0.59 nM, respectively. Interference studies also proved that the chelating ligand neocuproine (NC) displayed high selectivity for the determination of Cu(II) in the presence of various metal ions. The Cu(II) sensor was successfully applied to food and environmental samples, achieving acceptable and high recovery rates (89.3
