High sensitivity detection of a protein biomarker interleukin-8 utilizing a magnetic modulation biosensing system

Biomarkers are an important component of medical diagnosis and patient management. There is an ongoing need for accurate, precise, and reproducible methods to detect and quantify biomarkers to help diagnose diseases. High-sensitivity assays for biomarker measurements have been developed to address this need, but they are usually done in laboratories, using complex and expensive equipment that allows for high throughput testing. To enable health care providers to make more timely decisions, biomarker measurement can be performed at the patient's bedside, but the devices used in these settings are associated with less precise and less sensitive performance. The solution is a small footprint technology that enables more sensitive measurement of biomarkers, using simple instrumentation. Here, we utilize a novel diagnostic platform, named Magnetic Modulation Biosensing (MMB), and demonstrate its capabilities in high-sensitivity biomarker detection. MMB uniquely combines magnetic and fluorescent labeling to measure ultra-low biomarker concentrations. We demonstrate the system's capabilities using a commercially-available assay for detection and quantification of human Interleukin-8 over several orders of magnitude. The results show that MMB has a 6-log dynamic range available for detection and is capable of detecting 0.08 ng/L of IL-8 in blood plasma, a sensitivity comparable to current state-of-the-art laboratory assays.