Aptamer-Capped nanoporous anodic alumina for Staphylococcus aureus detection

Abstract

The development of new detection systems for an accurate and rapid identification of pathogens has become an essential challenge in the biomedical field. Herein a highly selective platform based on aptamer-gated nanomaterials for specific Staphylococcus aureus detection is presented. In the proposed design, a nanoporous anodic alumina (NAA) scaffold is loaded with the fluorescent indicator rhodamine B, while pores entrances are capped by a DNA aptamer which selectively recognizes S. aureus cells in less than 1 h. When S. aureus cells are present, the solid is selectively uncapped, and the dye is released to the medium. This nanodevice allows the detection of bacterial concentrations between 2 and 5 CFU mL−1 (in buffer and blood, respectively) and it has demonstrated excellent behavior in terms of specificity and robustness. A set of 25 different clinical samples are analyzed using this simple procedure obtaining excellent results, which agree with conventional hospital reference techniques for the identification of S. aureus. This new method is sensitive, rapid and low cost, and avoids steps such as polymerase chain amplification reaction, which makes it suitable for use in point-of-care detection systems.