Selenium is an essential micronutrient and is well known for its role in regulating metabolism. However, it is also highly toxic in some of its forms and above certain concentration levels. Amorphous selenium nanoparticles (SeNPs) are extremely unstable and convert into non-bioactive or gray elemental selenium with crystal-type structures due to aggregation, which limits its antioxidant and anti-tumor activities. To overcome these limitations, monodisperse SeNPs were obtained by stabilizing SeNPs with glucan and rosmarinic acid (RA) via Se–O bonds and polysaccharide–polyphenol interactions. The prepared glucan-RA-SeNPs were found much more stable than both SeNPs and glucan-stabilized SeNPs. Meanwhile, glucan-RA-SeNPs displayed enhanced bioactivities including an improved free radical scavenging ability and an increased cytotoxicity toward cancer cells. The underlying mechanism might be related to caspase activation by glucan-RA-SeNPs, thus overproducing intracellular reactive oxygen species and eventually resulting in cancer cell apoptosis. Our work proposes a feasible strategy for improving the structure–bioactivity of SeNPs through polysaccharide–polyphenol interaction.

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Developing robust and sensitive food safety detection methods is important for human health. Electrochemiluminescence (ECL) is a powerful analytical technique for complete separation of input source (electricity) and output signal (light), thereby significantly reducing background ECL signal. ECL biosensors have attracted considerable attention owing to their high sensitivity and wide dynamic range in food safety detection. In this review, we introduce the principles of ECL biosensors and common ECL luminophores, as well as the latest applications of ECL biosensors in food analysis. Further, novel nanomaterial assembly strategies have been progressively incorporated into the design of ECL biosensors, and by demonstrating some representative works, we summarize the development status of ECL biosensors in detection of mycotoxins, heavy metal ions, antibiotics, pesticide residues, foodborne pathogens, and other illegal additives. Finally, the current challenges faced by ECL biosensors are outlined and the future directions for advancing ECL research are presented.

Mercury ion (Hg 2+ ) is toxic and can severely damage the environment and human health. Therefore, sensitive and selective Hg 2+ detection methods are needed. Here, we synthesized dendritic silica nanospheres (DSN) with central-radial porous structures and immobilized Au and Pt nanoparticles into their pores. The synthesized DSN with Au and Pt nanoparticles (AuPt@DSN) exhibited superior peroxidase-like activity, stability, and dispersibility. We found that AuPt@DSN can specifically reduce Hg 2+ , leading to the decreased catalytic activity of the nanozymes. Under optimal testing conditions, the AuPt@DSN material was efficiently used for the visual detection of Hg 2+ . The detection limit was 8.58 pM with a linear range from 0.1 nM to 10 μM. Selectivity toward Hg 2+ has also been demonstrated in aqueous solutions in the presence of other metal ions. This strategy is simple to utilize and has a low cost and rapid response. The practicability was further investigated by analyzing complex water samples, which suggests its potential for mercury evaluation in environmental samples.

Food safety issues have become a major threat to public health and have garnered considerable attention. Rapid and effective detection methods are crucial for ensuring food safety. Recently, nanostructured fluorescent materials have shown considerable potential for monitoring the quality and safety of food because of their fascinating optical characteristics at the nanoscale. In this review, we first introduce biomaterials and nanomaterials for food safety analysis. Subsequently, we perform a comprehensive analysis of food safety using fluorescent biosensors based on nanomaterials, including mycotoxins, heavy metals, antibiotics, pesticide residues, foodborne pathogens, and illegal additives. Finally, we provide new insights and discuss future approaches for the development of food safety detection, with the aim of improving fluorescence detection methods for the practical application of nanomaterials to ensure food safety and protect human health.