9th August 2018 

Aptamers continue to demonstrate advantages in platforms and applications which require specific detection of small molecule targets.

There has been a growth in the use of point of care devices across a range of applications and assay types due to a need for rapid and reliable analysis (Vashist 2017). Aptamers are perfectly suited for these devices where specific characteristics are needed for the device to function due to their tuneable function and low production costs (Song 2012). Here Yang, et al present a method for rapid, low-cost detection of aflatoxin B1 (AFB1), a potent carcinogen, mutagen which is produced by certain strains of the Aspergillus fungi and can be found in most grains (Foster 2001). 

With the rapid development of economies and improvement of living conditions, food safety has become an important issue in the current society. Aflatoxin B1 (AFB1) produced mainly by Aspergillus flavus and Aspergillus parasiticus, exists in various kinds of food (bread, pastry, cake) and feedstuff products (such as maize, groundnut, and peas) mainly through their
exposure in wet environment at room temperature. The most toxic and carcinogenic among the major species of concern aflatoxins is AFB1. The long-term exposure to AFB1 may lead to severe liver-related disease in human beings and animals (Yilmaz 2018).

Despite recent developments on portable on-site sensors of the complex and expensive preparation of recognition elements of aflatoxins still limits their wide application. In this paper, by the fast, low-cost and stable recognition of aptamer DNA-AFB1 via a DNA walking machine on a personal glucose meter (PGM), a portable aptasensor was constructed for the on-site detection of AFB1 in food matrixes. In such an assay protocol, the target could trigger the DNA walker autonomously moving on the electrode surface, propelled by unidirectional Pb2+-specific DNAzyme digestion, which could amplify the signal and separate the signal probe as well for further quantification by the PGM.

Sandeep Kumar Vashist, 2017 Point-of-Care Diagnostics: Recent Advances and Trends, Biosensors (Basel). 7(4), 62.

Kyung-Mi Song, Seonghwan Lee, and Changill Ban, 2012. Aptamers and Their Biological Applications, Sensors (Basel). 12(1), 612–631.

P.L. Fostera, W.A. Roscheb, 2001 Aflatoxins,  Encyclopedia of Genetics. 20-21.

Yilmaz S., Kaya E., Karaca A., Karatas O., Aflatoxin B1 induced renal and cardiac damage in rats: Protective effect of lycopene. Research in Veterinary Sciences. 2018 Jul 23;119:268-275