The accumulation of pesticide residues poses a significant threat to the health of people and the surrounding ecological systems. However, traditional methods are not only costly but require ...expertise in analysis. An electrochemiluminescence (ECL) aptasensor was developed using chitosan and molybdenum disulfide (CTS-MoS2), along with acetylene black (AB@CTS) for the rapid detection of malathion residues. Due to the weak interaction force, simple composite may lead to uneven dispersion; MoS2 and AB were dissolved in CTS solution, respectively, and utilized the biocompatibility of CTS to interact with each other on the electrode. The MoS2 nanosheets provided a large specific surface area, enhancing the utilization rate of catalytic materials, while AB exhibited excellent conductivity. Additionally, the dendritic polylysine (PLL) contained numerous amino groups to load abundant luminol to catalyze hydrogen peroxide (H2O2) and generate reactive oxygen species (ROS). The proposed ECL aptasensor obtained a low detection limit of 2.75 × 10−3 ng/mL (S/N = 3) with a good detection range from 1.0 × 10−2 ng/mL to 1.0 × 103 ng/mL, demonstrating excellent specificity, repeatability, and stability. Moreover, the ECL aptasensor was successfully applied for detecting malathion pesticide residues in authentic samples with recovery rates ranging from 94.21% to 99.63% (RSD < 2.52%). This work offers valuable insights for advancing ECL sensor technology in future applications.
In this work, a novel ternary nanocomposite of PEI/RuSi-MWCNTs was designed and synthesized for the first time, which an ultrasensitive and self-enhanced electrochemiluminescent (ECL) aptasensor was ...developed for the detection of profenofos residues in vegetables. The self-enhanced complex PEI-Ru (II) enhanced the emission and stability of ECL, and the multi-walled carbon nanotubes (MWCNTs) acted as an excellent carrier and signal amplification. The PEI/RuSi-MWCNTs were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive spectrometer (EDS). The incorporation of gold nanoparticles (AuNPs) improved the performance of the sensor and provided a platform for the immobilization of the aptamer. The results of the experiment showed that the presence of profenofos significantly suppressed the electrochemiluminescence intensity of the sensor. The detection sensitivity of the aptamer sensor was in the range of 1 × 10−2 to 1 × 103 ng/mL. Under optimal conditions, the limit of detection (LOD) of the sensor for profenofos was 1.482 × 10−3 ng/mL. The sensor had excellent stability, reproducibility and specificity. The recoveries of the sensor ranged from 92.29 % to 106.47 % in real sample tests.
•Ternary PEI/RuSi-MWCNTs self-enhanced nanocomposites were prepared.•Preparation of sensors based on PEI/RuSi-MWCNTs for the detection of profenofos.•The sensor could detect profenofos in the range of 1 × 10−2∼1 × 103 ng/mL.•Profenofos levels in three vegetables were detected using sensors.
In this paper, an electrochemical sensor based on a dual recognition strategy of molecularly imprinted polymers (MIPs) and aptamer (Apt) has been designed for the high sensitivity detection of ...chloramphenicol (CAP). Here, MIPs and Apt have provided dual recognition sites to greatly improve the specific recognition ability of the sensor. Chitosan-multi-walled carbon nanotubes (CS-MWNTs) and AuNPs (gold nanoparticles) have been used for their excellent electrical conductivity. When CAP existed in the detection environment, the imprinted cavities with specific recognition ability bound to CAP through forces such as hydrogen bonds. It hindered the rate of electron transfer and resulted in a decrease in current value. Quantitative detection of CAP could be achieved after analyzing the relationship between the concentration of CAP and the change of current value. After optimizing the experimental parameters, the detection range of the sensor was 10-8 g/L-10-2 g/L with the limit of detection of 3.3 × 10-9 g/L, indicating that the sensor had a high practical application potential.
The single-atom iron nanozyme (SA-Fe-NZ) exhibits high catalytic activity and excellent electron transfer efficiency in biosensors. However, the binding of bioreceptors to the surface of SA-Fe-NZ ...results in a decrease in the catalytic activity of the nanozyme due to its toxic effects. We utilized the toxic effects and excellent electrochemical properties of the SA-Fe-NZ to successfully construct a smartphone-assisted dual-mode biosensor. The complex formed by the binding of organophosphorus pesticides (OPs) to the aptamer exhibited toxic effects and inhibited the catalytic activity of the nanozyme, preventing the colorimetric substrate from being catalyzed. Simultaneously, the aptamers labeled with electrochemical signal molecules approached the electrode surface, causing a change in the electrochemical signal. The results demonstrated that the constructed broad-spectrum aptamer biosensor exhibited a low limit of detection of 3.55 fM and a wide linear range of 10-13-10-2 M, allowing for qualitative and quantitative detection of multiple OPs in vegetables.
•AFB1 and total aflatoxin were detected by SWIR hyperspectral imaging innovatively.•Spatio-temporal distribution patterns of aflatoxin in peanut kernels were analyzed.•Aspergillus flavus ...contamination was identified in peanut kernels.•Aflatoxins were classified with safety limits in contaminated peanut kernels.
Aflatoxin contamination in peanut kernels seriously harms the health of humans and causes significant economic losses. Rapid and accurate detection of aflatoxin is necessary to minimize its contamination. However, current detection methods are time-consuming, expensive and destructive to samples. Therefore, short-wave infrared (SWIR) hyperspectral imaging coupled with multivariate statistical analysis was used to investigate the spatio-temporal distribution patterns of aflatoxin, and quantitatively detect the aflatoxin B1 (AFB1) and total aflatoxin in peanut kernels. In addition, Aspergillus flavus contamination was identified to prevent the production of aflatoxin. The result of validation set demonstrated that SWIR hyperspectral imaging could predict the contents of the AFB1 and total aflatoxin accurately, with residual prediction deviation values of 2.7959 and 2.7274, and limits of detection of 29.3722 and 45.7429 μg/kg, respectively. This study presents a novel method for the quantitative detection of aflatoxin and offers an early warning system for its potential application.
Food safety is an important cornerstone of protecting human health and life. Therefore, it is of great significance to detect possible pollutants in food sensitively and efficiently. Molecularly ...imprinted polymers (MIPs) and metal-organic frameworks (MOFs) have been widely used in the adsorption and detection of food pollutants. However, traditional MIPs have problems such as uneven loading of the imprinted cavity and slow mass transfer efficiency. While the adsorption of MOFs has low specificity and cannot accurately identify target molecules. Therefore, some researchers have taken advantage of the high specific recognition abilities of MIPs and the large specific surface areas, high porosity and easy functionalization of MOFs to combine MOFs with MIPs, and have achieved a series of important results in the field of food safety detection. This paper reviews the research progress of the application of MOFs-MIPs in the field of food safety detection from 2019 to 2024. It furnishes researchers interested in this domain with a rapid and comprehensive grasp of the latest research status, it also offers them a chance to anticipate future development trends, thereby supporting the continuous advances of MOFs-MIPs in food safety detection.
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•Application of MOFs-MIPs in the field of food safety is reviewed for the first time.•Application of MOFs-MIPs in the detection of eight kinds of food pollutants.•MOFs-MIPs have potential applications in food safety detection field.•The key role of each component in MOFs-MIPs.•Challenges and future trends of MOFs-MIPs were discussed.
In this study, a novel uniform manifold approximation and projection combined-improved simultaneous optimization genetic algorithm-convolutional neural network (UMAP-ISOGA-CNN) algorithm was ...proposed. The improved simultaneous optimization genetic algorithm (ISOGA) combined with convolutional neural network (CNN) to optimize the architecture, hyperparameters, and optimizer of the CNN model simultaneously. Additionally, a uniform manifold approximation and projection (UMAP) method was used to visualize the feature space of all feature layers of the ISOGA-CNN model. The UMAP-ISOGA-CNN algorithm combined with visible and near-infrared hyperspectral imaging was used to identify peanut kernels contaminated with Aspergillus flavus and to distinguish their storage time, which is essential for the food industry to monitor the freshness of products. Overall, the UMAP-ISOGA-CNN algorithm provides useful insights into the feature space of the ISOGA-CNN model, contributing to a better understanding of the model's internal mechanisms. This study has practical implications for the food industry and future research on deep learning optimization.
Process of optimizing the initial CNN model using ISOGA. Display omitted
•A novel UMAP-ISOGA-CNN algorithm was proposed.•Aspergillus flavus contamination was identified in peanut kernels.•Useful insights were provided for the optimization of deep learning models.•UMAP was used to visualize the feature layers of the ISOGA-CNN model.
Pathogenic bacteria are primarily kinds of food hazards that provoke serious harm to human health via contaminated or spoiled food. Given that pathogenic bacteria continue to reproduce and expand ...once they contaminate food, pathogenic bacteria of high concentration triggers more serious losses and detriments. Hence, it is essential to detect low-dose pollution at an early stage with high sensitivity. Aptamers, also known as "chemical antibodies", are oligonucleotide sequences that have attracted much attention owing to their merits of non-toxicity, small size, variable structure as well as easy modification of functional group. Aptamer-based bioanalysis has occupied a critical position in the field of rapid detection of pathogenic bacteria. This is attributed to the unique advantage of using aptamers as recognition elements in signal amplification strategies. The signal amplification strategy is an effective means to improve the detection sensitivity. Some diverse signal amplification strategies emphasize the synthesis and assembly of nanomaterials with signal amplification capabilities, while others introduce various nucleic acid amplification techniques into the detection system. This review focuses on a variety of signal amplification strategies employed in aptamer-based detection approaches to pathogenic bacteria. Meanwhile, we provided a detailed introduction to the design principles and characteristics of signal amplification strategies, as well as the improvement of sensor sensitivity. Ultimately, the existing issues and development trends of applying signal amplification strategies in apta-sensing analysis of pathogenic bacteria are critically proposed and prospected. Overall, this review discusses from a new perspective and is expected to contribute to the further development of this field.
In order to achieve a highly sensitive detection of procymidone in vegetables, three paper-based biosensors based on a core biological immune scaffold (CBIS) were developed, which were time-resolved ...fluorescence immunochromatography strips with Europium (III) oxide (Eu-TRFICS). Goat anti-mouse IgG and europium oxide time-resolved fluorescent microspheres formed secondary fluorescent probes. CBIS was formed by secondary fluorescent probes and procymidone monoclonal antibody (PCM-Ab). The first type of Eu-TRFICS (Eu-TRFICS-(1)) fixed secondary fluorescent probes on a conjugate pad, and PCM-Ab was mixed with a sample solution. The second type of Eu-TRFICS (Eu-TRFICS-(2)) fixed CBIS on the conjugate pad. The third type of Eu-TRFICS (Eu-TRFICS-(3)) was directly mixed CBIS with the sample solution. They solved the problems of steric hindrance of antibody labeling, insufficient exposure of antigen recognition region and easy loss of activity in traditional methods. They realized multi-dimensional labeling and directional coupling. They replaced the loss of antibody activity. And the three types of Eu-TRFICS were compared, among which Eu-TRFICS-(1) was the best detection choice. Antibody usage was reduced by 25% and sensitivity was increased by 3 times. Its detection range was 1–800 ng/mL, the limit of detection (LOD) was 0.12 ng/mL with the visible LOD (vLOD) of 5 ng/mL.
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•Time-resolved fluorescent microspheres were applied to CBIS.•The monoclonal antibody usage was reduced by 25% prepared by the CBIS.•The CBIS connect multiple microspheres to one antibody molecule.•The linear range of Eu-TRFICS-(1) used to detect procymidone is 1–800 ng/mL.•Three kinds of Eu-TRFICS used to detect procymidone are constructed and compared.
As an organochlorine pesticide, procymidone has become an increasing serious problem in vegetables in recent years. In order to solve a series of problems such as low sensitivity of the immunological ...methods, a time-resolved fluorescent immunoassay strip (TRFIAS) was developed with low limit of detection (LOD). Based on the principle of antigen-antibody immune competition, TRFIAS could detect procymidone in vegetables. After the targets being added, the samples were incubated at 37°C for 10 min. TRFIAS was observed under a UV lamp of 365 nm. The results were processed by ImageJ software to complete the qualitative and quantitative analysis of TRFIAS. Under the optimal working conditions, a linear range of TRFIAS was 5–250 ng/mL with a LOD of 0.33 ng/mL and a visual limit of detection (VDL) of 50 ng/mL. And the TRFIAS had good specificity, precision and accuracy. Comparing the results of TRFIAS with those of ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), the two assays were in good agreement. Therefore, TRFIAS has the advantages of high sensitivity, high specificity, simple operation and relatively short assay time. Meanwhile, it shows absolutely great advantages in both quantitative and qualitative analysis.
•Time-resolved fluorescence immunochromatography assay is applied to test procymidone.•Time-resolved fluorescence immunochromatography assay has higher sensitivity.•Test strips have short assay time and simple operation.
