Sudan dye is generally used as a coloring agent in textile and cosmetic industries. However, Sudan dye exhibits potentials to cause cancer, toxicity, and allergy because of its metabolites including amines and naphthol related substances. Despite banning Sudan dye, the Sudan dye is used by many unscrupulous food manufacturers for enhancing food appearance. This paper introduces a new aptamer based on Sudan III detection methods. An in vitro selection and amplification method named SELEX (Systematic Evolution of Ligands by Exponential Enrichment) is employed to screen out Sudan III specific aptamer. The desired aptamer is obtained after 12 rounds of screening and cloning. To establish aptamer affinity and specificity for Sudan III, ELONA (enzyme‐linked oligonucleotide assay) and dot blot analyses are performed. ELONA assay indicates that 100 nM is the optimum concentration of the aptamer for Sudan III detection, while the minimum detection limit of Sudan III is 4 ng/well. The aptamer exhibits stable secondary structure with the stem‐loop and G‐quadruplex in the main structure. The selected single ssDNA aptamer C07 demonstrates binding affinity and the highest specificity to Sudan III (C07: KD = 22.37 ± 3.943 nmol L−1). Based on the results, a good correlation is observed between aptamer C07 and Sudan III and it is concluded that the new Sudan III specific aptamer has potential to be applied for rapid and accurate detection of the Sudan III in food products. Practical Applications: Examination of the chili sauce sample in a simulation experiment indicates that the aptamer C07 can be applied to rapid detection in foods. The nucleic acid aptamers‐based food detection method has the advantages of high sensitivity, specificity, easy operation, short detection time, and low cost. It can realize the rapid detection of illegal additives in foods, which has a great significance in the field of food safety research. The SELEX method is used to select a new Sudan III specific aptamer. ELONA and Dot blot assays further suggest that aptamer C07 can be used for selective detection of Sudan III. Therefore, the detection in chili sauce samples offers feasibility for more complex samples.

A sandwich lateral flow strip assay (LFSA) using a couple of aptamers functionalized with gold nanoparticles (AuNPs) was designed to assess the presence of rongalite in agrifood products. More specifically, a biotin-labeled primary A09 aptamer immobilized on a streptavidin-coated membrane and a secondary B09 aptamer conjugated with AuNPs were developed as capturing and signaling probes, respectively. This system allows the successful and direct detection of rongalite in food samples with concentrations as low as 1 μg/mL, simply by observing the color change of LFSA control and test line.

Amanita poisoning is one of the most deadly types of mushroom poisoning. α-Amanitin is the main lethal toxin in amanita, and the human-lethal dose is about 0.1 mg/kg. Most of the commonly used detection techniques for α-amanitin require expensive instruments. In this study, the α-amanitin aptamer was selected as the research object, and the stem-loop structure of the original aptamer was not damaged by truncating the redundant bases, in order to improve the affinity and specificity of the aptamer. The specificity and affinity of the truncated aptamers were determined using isothermal titration calorimetry (ITC) and gold nanoparticles (AuNPs), and the affinity and specificity of the aptamers decreased after truncation. Therefore, the original aptamer was selected to establish a simple and specific magnetic bead-based enzyme linked immunoassay (MELISA) method for α-amanitin. The detection limit was 0.369 μg/mL, while, in mushroom it was 0.372 μg/mL and in urine 0.337 μg/mL. Recovery studies were performed by spiking urine and mushroom samples with α-amanitin, and these confirmed the desirable accuracy and practical applicability of our method. The α-amanitin and aptamer recognition sites and binding pockets were investigated in an in vitro molecular docking environment, and the main binding bases of both were T3, G4, C5, T6, T7, C67, and A68. This study truncated the α-amanitin aptamer and proposes a method of detecting α-amanitin.

Bacterial infection, tissue hypoxia, inflammatory and oxidative stress are several keyproblems in wound healing of chronic infections. Herein, a multi-enzyme-like activitiesmultifunctional hydrogel made up mussel-inspired carbon dots reduced Ag(CDs/AgNPs) and...

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