Photothermal-driven magnetic ZnFe2O4 "three-in-one" nanoplatform for interfacial enrichment and rapid screening of 3-monochloropropane-1,2-diol in edible oils.

Signal-enhanced photoelectrochemical aptasensor for the detection of sulfadiazine based on Fe3O4/3D g-C3N4 heterojunction.

The contamination of the environment with the sulfadiazine (SDZ) antibiotic poses a significant risk to human and animal health and contributes to the emergence of drug-resistant bacteria. Conventional detection methods are often time-consuming and require sophisticated instrumentation. Herein, we developed a sensitive SDZ detection method based on a high-performance photoelectrochemical (PEC) aptasensor. Using an iron oxide (Fe3O4) functionalized three-dimensional graphitic carbon nitride (3DCN) nanocomposite. The 3DCN substrate was initially prepared through supramolecular self-assembly employing an ionic liquid as a template, followed by thermal polycondensation. Then, Fe3O4 nanoparticles bearing abundant hydroxyl groups were covalently anchored onto the 3DCN matrix via a solvothermal method. The incorporation of Fe3O4 broadened the visible-light absorption, facilitating charge separation and transport, and acting as an effective electron donor. Operating in a "signal-on" mode, the proposed aptasensor exhibited excellent analytical performance with a broad linear range (0.1 nM-1000 nM), a low detection limit (215 pM), and outstanding selectivity, stability, and reproducibility. The practical applicability was successfully validated by detecting SDZ in river water and milk with recoveries of 98.1-99.8%. Overall, the Fe3O4/3DCN-based PEC aptasensor is a robust, sensitive, cost-effective with good potential for food safety, environmental monitoring, and public health protection.

In Situ Engineering of S-Scheme Bi2O3/Zn3In2S6 Heterojunctions on Paper-Based Architectures for Dual-Mode Photoelectrochemical-Electrochemical Detection of Carcinoembryonic Antigen.

A highly sensitive dual-mode immunosensing platform, integrating photoelectrochemical (PEC) and electrochemical detection via the in situ architectural engineering of an S-scheme Bi2O3/Zn3In2S6 heterojunction directly onto cellulose fiber scaffolds, which represents a versatile architecture for the early diagnosis of diverse clinical biomarkers.

Lanthanide-based luminescent metal–organic framework as an optical sensing platform for rapid and reliable assessment of antioxidant activity in food samples

A rapid and sensitive fluorescence-based method for antioxidant capacity assessment was developed using a lanthanide-based metal–organic framework (LVMOF-1). The Eu3+-MOF, incorporating an electron-deficient viologen ligand, enables host–guest interactions with phenolic antioxidants, leading to a quantitative quenching of a composite optical signal driven by a resonance convolution of native Eu3+ photoluminescence and second-order scattering, inner filter effect and colloidal modulation. Using gallic acid as a model compound, the system exhibited a non-linear Langmuir-type response that was successfully linearized through logarithmic transformation, enabling reliable quantification of total antioxidant capacity over an extended concentration range. The method showed excellent analytical performance, with a limit of detection of 0.0077 mg L–1, good linearity (R2 = 0.992), and reproducibility below 7% RSD. Compared to conventional assays (Folin–Ciocalteu, DPPH, ABTS, and FRAP), it provided higher sensitivity, shorter analysis time (≤ 2 min), and improved robustness in complex matrices, inherently minimizing color-induced spectral interferences due to the high sensitivity of fluorescence detection. Application to honey, tea, and wine samples showed very strong correlations with established methods (Pearson r = 0.947–0.996). These results were further supported by Bland–Altman analysis, which confirmed good overall agreement with method-dependent differences, and principal component analysis (PCA), which revealed a common underlying antioxidant capacity dimension. Additionally, the LVMOF-1 assay showed the best greenness (AGREE score 0.59) and lowest cost (0.63 € per sample), highlighting its potential as a sustainable alternative for routine antioxidant screening.

Ferrocene-functionalized NH2-UiO-66/MoO3 ratiometric electrochemical sensing platform for efficient monitoring of levofloxacin

A high-performance Au@γ-Al2O3 SERS substrate for reliable monitoring of trimethoprim.

Novel Au@γ-Al2O3 nanoparticles were synthesized and used as a substrate for the determination of trimethoprim (TPM) in samples by surface-enhanced Raman spectroscopy (SERS). The newly prepared Au@γ-Al2O3 nanoparticles were characterized by ultraviolet spectroscopy, infrared spectroscopy and scanning electron microscopy. The experimental conditions such as the volume of Au@γ-Al2O3 nanoparticles, pH, ionic strength and mixing time of nanoparticles and drugs in the system were optimized. Under the optimal conditions, the concentration range of TPM has a good linear relationship (ISERS = 107.99c + 44 870.51, c: nmol L-1, R2 = 0.9922) in the range of 3.33-300.00 nmol L-1. The LOD (S/N = 3) was 2.35 nmol L-1. The enhancement factor (EF) of the system in the detection of TPM was 4.23 × 106. The effects of several common interfering substances on the determination of TPM were studied (K+, Mg2+, Zn2+, Ca2+, Cu2+, glucose and monensin). No TPM was detected in chicken and duck samples. The recovery of TPM samples was from 97.90% to 102.91% with RSD values of 1.38%-4.41% (n = 5).

In2O3/CdS heterojunction-based photoelectrochemical sensor for therapeutic drug monitoring of rifampicin in clinical samples.

Rapid and reliable determination of rifampicin (RIF) is important for dose optimization and therapeutic drug monitoring during tuberculosis treatment. Herein, In2O3/CdS heterojunctions were fabricated through calcination followed by in situ CdS growth and employed as an efficient photoactive interface for photoelectrochemical RIF sensing. The In2O3/CdS heterojunction enhanced photoinduced charge separation and provided an amplified photocurrent background, while RIF induced a concentration-dependent photocurrent quenching response for signal-off PEC quantification. Under optimized conditions, the proposed sensor showed a linear response to RIF over the concentration range of 0.010-75 μM, with a detection limit of 1.45 nM (S/N = 3). The sensor exhibited satisfactory selectivity against common coexisting substances, as well as good repeatability and storage stability. Accurate RIF quantification was further achieved in spiked human serum, urine, and pharmaceutical capsule samples, affording recoveries of 97.73% and 103.49% with relative standard deviations below 4.1%. This work provides a sensitive and reliable PEC platform for RIF determination in complex biological and pharmaceutical matrices.