Colorimetric DNAzyme Biosensor for Convenience Detection of Enterotoxin B Harboring Staphylococcus aureus from Food Samples

Abstract

In the present study, a colorimetric DNAzymes biosensor strategy was devised in combination with immunomagnetic separation for rapid and easy detection of enterotoxin B harboring Staphylococcus aureus from food and clinical samples. The method employs immunocapture of S. aureus and amplification of seb gene by DNAzyme complementary sequence integrated forward primer and with specific reverse primer. The DNAzyme sequence integrated dsDNA PCR products when treated with hemin and TMB (3,3',5,5'-tetramethylbenzidine) in the presence of HO produce colorimetric signal. A linear relationship of optical signal with the initial template of seb was obtained which could be monitored by visually or spectrophotrometrically for qualitative and quantitative detection. The limit of detection for the assay was approximately 10 CFU/mL of seb gene harboring target. This method is convenient compared to gel based and ELISA systems. Further, spiking studies and analysis on natural samples emphasized the robustness and applicability of developed method. Altogether, the established assay could be a reliable alternative, low-cost, viable detection tool for the routine investigation of seb from food and clinical sources.

A novel electrochemical immunosensor based on Fe3O4@graphene nanocomposite modified glassy carbon electrode for rapid detection of Salmonella in milk

“…Among them, Salmonella Anatum is worldwide in distribution and is also a common cause of food poisoning in humans and animals (Hartmann and West, 1995;Hassan et al, 2017). Normally, after eating Salmonella contaminated food, humans, especially children, may experience symptoms such as vomiting, headache, and diarrhea (Ni et al, 2018). With the continuous expansion of the global population, the demand for high-nutrient foods such as milk has also increased rapidly (Yang et al, 2021).…”

“…Although traditional methods are reliable, it usually takes 4 to 7 d to get the test result (Abdalhai et al, 2014;Yu et al, 2017). Instrument analysis technology mainly includes surface plasmon resonance (SPR) biosensors (Chen et al, 2017), PCR (Mondal et al, 2018), and electrochemical sensors (Adkins et al, 2017;Soares et al, 2020;Huang et al, 2021). The SPR biosensors detect quickly but their application is limited by poor sensitivity (Wang et al, 2015).…”

Nanobodies Based on a Sandwich Immunoassay for the Detection of Staphylococcal Enterotoxin B Free from Interference by Protein A

“…Staphylococcus aureus is considered as one of the most common food-borne pathogens, whose pathogenic potential predominantly relies on the production of an impressive catalog of exotoxins known as staphylococcal enterotoxins (SEs). − These SEs are structurally similar toxic proteins with a molecular weight (MW) ranging from approximately 28 to 34 kDa, which show excellent thermal stability and resistance to proteolytic digestion . Moreover, intestinal cells are the specific targets of SEs, which leads to gastroenteritis, signified by diarrhea, vomiting, and gastric or intestinal inflammation, and even invoking toxic shock syndrome as a result of the presence of superantigens in a lower dose. , Therefore, accurate and reliable methods for the detection of SEs are vital for food safety, clinical diagnosis, and the environment.…”

“…Until now, various analytical methods have been employed for the detection and quantification of SE content in food, water, and even bodily fluids, such as serum. These techniques include enzyme-linked immunosorbent assays (ELISAs), , lateral flow platforms, polymerase chain reactions (PCRs), chemiluminescent assays, colorimetric sensors, , electrochemical assays, , and surface-enhanced Raman scattering assays . Most of these detection strategies demand complicated instruments, strict laboratory conditions, and trained personnel.…”

DNAzyme-Based Biosensors: Immobilization Strategies, Applications, and Future Prospective

“…DNAzyme-based biosensors have been used for widespread applications, given their strong detection capabilities and functionality within diverse environments. Namely, these biosensors have been used extensively for the detection of food contaminants, − pathogens, − metal ions, ,, and various clinically relevant biomarkers. − Compared to traditional detection methods, DNAzyme-based biosensors have shown robust accuracy, high detection sensitivity, and resilience to non-specific entities that can often hinder sensing cascades. , …”