Foodborne bacteria (including Salmonella, Escherichia coli, etc.) can cause a number of illnesses and result in social and economic losses. However, the conventional tools used in foodborne bacteria monitoring demonstrate poor specificity, while also being insensitive, labor-intensive and time-consuming. Thus, the development of easy-to-use and efficient detection methods that utilize innovative devices to address the aforementioned issues is warranted. Nanomaterial-based optical biosensors have been widely used in monitoring foodborne bacteria. This study offers an overview of the use of nanomaterial-based optical biosensors that have been applied in foodborne bacteria detection, with an emphasis on the different molecular recognition elements and the incorporation of diverse nanomaterials in the optical biosensors. In addition, this article compares the analytical performance of nanostructured biosensors and conventional techniques. Finally, the article concludes by identifying the key challenges of nanomaterial-based optical biosensors in the future. This will provide new ideas and good application prospects for the detection of harmful foodborne bacteria.

Food look good is more inclined to be bought, but transportation and storage can be difficult to maintain the attractive appearance and freshness of each food, microbial pollution is one of the major obstacles. Scientific advancements in pulsed electric field has shown its capability on the inactivation of microorganisms and maintain of high quality of food products. In this review, we summarized the basic principle of pulsed electric field technology, illustrated the bactericidal effect of common pathogenic bacteria in food such as Escherichia coli, Salmonella spp., Listeria monocytogenes and Mold spores, introduced application of pulsed electric field in fruit and vegetable processing, liquid food sterilization and the preservation of meat products, also proposed the future development direction of the application of pulsed electric field technology in food drying, thawing, and the extraction.

Zearalenone (ZEN) is harmful to animals and human beings, so it is very important to develop a rapid and sensitive method for the detection of ZEN. In this paper, we proposed a novel ZEN-monitoring method using two aptamers as recognition elements and EnGen LbaCas12a and Nt.AlwI nicking endonuclease as signal amplifiers. When ZEN was present, it bound to the aptamer Z0 and, Z1 was released into solution. The solution was then separated and the Nt.AlwI enzyme was added in order to form a nicking-enzyme cycle, thereby producing large amounts of the ssDNA Z3 for 30 min. The Z3 formed a CRISPR-Cas12a-Z3 complex with CRISPR-Cas12a, activated the trans-cleavage ability of Cas12a, cleaved the Quenched Reporter for 20 min, and underwent fluorescence recovery. The aptasensor was able to sensitively detect ZEN in the linear range of 1–1000 pg/mL, with a detection limit as low as 0.213 pg/mL. The detection time lasted for 2 h. Additionally, this detection technology can also be used to monitor other hazards.

Timely detection of Staphylococcus aureus (S. aureus) is critical because it can multiply to disease−causing levels in a matter of hours. Herein, a simple and sensitive DNA tetrahedral (Td) fluorescence signal amplifier with blue carbon quantum dots (bCDs) was prepared for sandwich detection of S. aureus. bCD was modified at the apex of Td, and an aptamer on Td was used to accurately identify and “adsorb” the amplifier to the surface of S. aureus. Atomic force microscopy (AFM) demonstrates the successful preparation of this signal amplifier. The fluorescence intensity emitted in this strategy increased 4.72 times. The strategy showed a stronger fluorescence intensity change, sensitivity (linear range of 7.22 × 10⁰–1.44 × 10⁹ CFU/mL with a LOD of 4 CFU/mL), and selectivity. The recovery rate in qualified pasteurized milk and drinking water samples was 96.54% to 104.72%. Compared with simple aptamer sandwich detection, these fluorescence signal amplifiers have improved fluorescence detection of S. aureus. Additionally, this fluorescent signal amplification strategy may be applied to the detection of other food pathogens or environmental microorganisms in the future.