[Biosensors and Bioelectronics] Multiplexed Nanoplasmonic Biosensor for One-step Simultaneous Detect
Development of rapid and multiplexed diagnostic tools is a top priority to address the current epidemic problem of sexually transmitted diseases. Here we introduce a novel nanoplasmonic biosensor for simultaneous detection of the two most common bacterial infections: Chlamydia trachomatis and Neisseria gonorrhoeae. Our plasmonic microarray is composed of gold nanohole sensor arrays that exhibit the extraordinary optical transmission (EOT), providing highly sensitive analysis in a label-free configuration. The integration in a microfluidic system and the precise immobilization of specific antibodies on the individual sensor arrays allow for selective detection and quantification of the bacteria in real-time. We achieved outstanding sensitivities for direct immunoassay of urine samples, with a limit of detection of 300 colony forming units (CFU)/mL for C. trachomatis and 1500 CFU/mL for N. gonorrhoeae. The multiplexing capability of our biosensor was demonstrated by analyzing different urine samples spiked with either C. trachomatis or N. gonorrhoeae, and also containing both bacteria. We could successfully detect, identify and quantify the levels of the two bacteria in a one-step assay, without the need for DNA extraction or amplification techniques. This work opens up new possibilities for the implementation of point-of-care biosensors that enable fast, simple and efficient diagnosis of sexually transmitted infections.
Maria Soler a, Alexander Belushkin a, Andrea Cavallini a, Carole Kebbi-Beghdadi b, Gilbert Greub b, Hatice Altug a, a Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland b Center for Research on Intracellular Bacteria (CRIB), Institute of Microbiology, University Hospital Center, University of Lausanne, Lausanne 1011, Switzerland Received 10 January 2017, Revised 16 March 2017, Accepted 20 March 2017, Available online 21 March 2017 http://dx.doi.org/10.1016/j.bios.2017.03.047