Development of a fluorescence aptasensor for rapid and sensitive detection of Listeria monocytogenes in food

In this study, a simple fluorescence aptasensor was developed for rapid and sensitive detection of Listeria monocytogenes in food. The aptasensor was comprised of two parts. Aptamer-functionalized upconversion nanoparticles (UCNPs) recognized and adhered to the L. monocytogenes cells and provided strong fluorescent signals. Aptamer-functionalized magnetic nanoparticles (MNPs), which also recognized and adhered to the cells, were used to concentrate the aptamer-UCNP/L. monocytogenes/aptamer-MNP complex. The fluorescence intensity was measured and calibrated to a concentration series of L. monocytogenes. A low limit of detection of 8 cfu mL(-1) was estimated from the range of 68 to 68 x 10(6) cfu mL(-1). Compared with other methods currently available, the proposed method had wider detection range and higher sensitivity. Furthermore, the selectivity and functionality when used to detect L. monocytogenes in real food samples suggest it may be useful for practical applications.

Automated summary

In this study, a simple fluorescence aptasensor was developed for rapid and sensitive detection of Listeria monocytogenes in food. The sensor showed a low limit of detection and wider detection range compared to other methods, with good selectivity and functionality in detecting L. monocytogenes in real food samples.