Ultra-Fast Detection of Pathogens and Protein Biomarkers Using a Low-Cost Silicon Plasmonic Biosensing Platform for Efficient Management of Sepsis at the Point of Care

In this paper, we report for the first time to our knowledge, a new versatile and future proof diagnostic platform for point of care applications that relies on a plasmonic-augmented silicon photonic biochip to detect both bacteria and protein biomarkers within minutes. As a proof-of-concept, we combine the detection of Escherichia coli (E. coli), one of the most encountered bacterial pathogens involved in sepsis, and C-reactive protein (CRP) detection, a disease severity indicator, in a single biochip compatible with CMOS semiconductor manufacturing, that can host up to 8 hybrid detection assays. Each biosensor exploits a 70 μm long aluminum plasmonic transducer within a silicon nitride waveguide-based Mach-Zehnder Interferometer. Each aluminum surface was silanized and biomodified with specific antibodies. Biosensing experiments revealed that CRP can be detected in patient serum samples at concentrations of clinical relevance and E. coli at as low as 10 cells/ml within 13 minutes. Results are in good agreement with preceding numerical simulation results. Finally, the modular nature of the reported biosensing platform makes it scalable and customizable allowing different combinations of tests on the same biochip, enabling multiplexed detection of pathogens or combined detection of nearly any sepsis related target such as proteins, bacteria, and viruses.