21st May 2019
Food and environmental monitoring is one of the most important aspects of dealing with recent threats to human well-being and ecosystems. Ensuring food safety is a top priority of authorities and professional players in the food supply chain.
One of the key challenges to determine the safety of food and guarantee a high level of consumer protection is the availability of fast, sensitive and reliable analytical methods to identify specific hazards associated to food before they become a health problem. The limitations of existing methods have encouraged the development of new technologies, among them biosensors. Success in biosensor design depends largely on the development of novel receptors with enhanced affinity to the target, while being stable and economical.
Aptamers fulfill these characteristics, and thus have surfaced as promising alternatives to natural receptors.
Di et al (2017) discuss a way of establishing a rapid, sensitive and real time method for the detection of Salmonella enteritidis.
Current processes take at least 7 days to get a clear diagnosis and the pre-treatment of the sample is complex. Therefore, an SPR-based biosensor has advantages of high sensitivity, no labelling and is rapid. The testing of food samples for Salmonella enteritidis, was carried out by homogenizing the food sample and was then treated by multiple centrifugation rounds and tested. To test cross-reactivity of the aptamer, four kinds of pathogenic bacteria were used in the binding experiments.
The results show that the aptamer was highly specific for Salmonella enteritidis. A standard curve for testing Salmonella enteritidis was created and showed that the aptamer sensor can detect from 2 to a million bacteria.
They then tested four food samples from a supermarket, chicken, pork, shrimp and fish and they were able to detect Salmonella enteritidis levels in those samples and further verify them in a plate count experiment.
By using commercially available instruments, it is easy to apply aptamers to various useful applications. If you would like to learn more about working with aptamers or would like to discuss the custom development service we offer, please get in touch using the form below.
Di, W.T., Du, X.W., Pan, M.F. and Wang, J.P., 2017, September. The SPR detection of Salmonella enteritidis in food using aptamers as recognition elements. In IOP Conference Series: Materials Science and Engineering (Vol. 231, No. 1, p. 012114). IOP Publishing. https://iopscience.iop.org/article/10.1088/1757-899X/231/1/012114/meta