Nanobiossensor por ressonância plasmônica de superfície para detecção de patógenos

Abstract

The bacterium Escherichia coli (E. coli) and the parasite Taenia solium (T.solium) are microorganisms that cause infections in humans. Their main detection methods consist of laboratory analyzes carried out by expensive equipment and reagents, and even so, it can take days to complete the results. In this context, this research presents the design of nanobiosensors by suspensions of gold nanoparticles (AuNPs) and by plastic optical fiber (POF) in a “U” shape coated with either gold nanofilm or coated with AuNPs for E. coli and T. solium detection. POF and nanostructures were used because they allow the development of diagnosis and detection systems by remote monitoring and in real time in an easy-to-handle instrumentation, accurate, and low costly. The nanofilm was produced by cathodic deposition in a sputtering chamber and the AuNPs by chemical synthesis. The sensors were evaluated for stability, variability, and sensitivity. The POF nanobiosensors with gold nanofilm showed a detection limit for E. coli bacteria of 1.5 x 103 CFU/mL. The AuNPs suspension containing antibody for the capture of T. solium antigens showed a detection limit higher than 0.1 µg/mL, corresponding to the concentration range found in human blood. The POF nanobiosensor containing AuNPs showed a sensitivity of 159.43 nm/RIU. Therefore, one tool turns out that this technology can be efficient for routine analysis in scheduled clinics