The accurate determination of histamine in fish is imperative for food safety, given the toxic nature of this biogenic amine . This study presents an innovative colorimetric aptasensor for the ultrasensitive detection of histamine in fish, utilizing nanozymes based on magnetic metal-organic frameworks coated with Pt nanoparticles (Fe 3 O 4 @MOF@Pt), which exhibit high peroxidase-like catalytic activity, magnetism, and superior optical properties. The surface of Fe 3 O 4 @MOF@Pt nanozymes were modified with DNA strands complementary to the histamine aptamer , creating effective colorimetric probes. In the presence of histamine, these colorimetric probes compete with histamine molecules for aptamer binding on the enzyme plate. Color development is triggered by adding a TMB and H 2 O 2 substrate solution to the enzyme plate. This competitive binding-based aptasensor allows for rapid and accurate histamine quantification within a linear range of 10 pM to 10 μM, and a notable detection limit of 6.23 pM. Furthermore, the sensor demonstrated excellent specificity, distinguishing histamine from l -histidine and other biogenic amines. Tested on mackerel samples, the aptasensor showed spiked recoveries of 91.4%–109.6%, validating its practical applicability. This sensor offers an ultrasensitive, specific, and reusable tool for histamine detection, representing a significant advancement in ensuring the safety of fish products.
A lateral flow immunoassay strip (LFIAS) is one of the most frequently rapid test technologies for carbofuran (CAR). Nevertheless, the LFIAS has a poor quantitative capability and low sensitivity. And, it also requires often complex sample handling steps, making testing time longer. In this study, Fe 3 O 4 nanoparticles were successively modified with MIL-100(Fe)-based metal-organic framework (MOF) and chloroplatinic acid hexahydrate to obtain a core-shell complex of Fe 3 O 4 -MOF-Pt. The complex had a peroxidase-mimicking activity catalytic function that enabled signal amplification and sensitivity enhancement. Upon coupling with carbofuran monoclonal antibody (CAR-mAb), the magnetic separation properties of the probe enabled target-specific enrichment. The LFIAS based on Fe 3 O 4 -MOF-Pt nanocomposites could detect CAR in the range of 0.25–50 ng mL −1 with a limit of detection (LOD) of 0.15 ng mL −1 , enabling colorimetric and catalytic analysis. In addition, the method showed high specificity and stability for detecting CAR in various vegetables, and recovery rates of the spiked samples were 91.40%−102.40%. In conclusion, this study provided one-stop detection of “target enrichment-visual inspection”. While lowering the LOD, it reduced the detection time and improved the detection efficiency. The multifunctional Fe 3 O 4 -MOF-Pt nanocomposite provides an idea for the construction of novel multifunctional probes to improve the detection performance of conventional LFIAS.
危险品化学品经营许可证（带存储）