Spot Immunomagnetic Enrichment Device for Rapid Detection of Pathogens in Peripheral Blood

Microbial infection is a leading cause of mortality and morbidity worldwide. Due to lack of rapid and affordable diagnostics test, patients consume broad spectrum antibiotics without diagnostic confirmation of the pathogen, leading to development of antibiotics resistance among microbes. Detection of pathogen is challenging particularly when only few cells per mL are present among billion other blood cells. A portable and cost‐effective spot immunomagnetic enrichment device has been developed that allows concentration of cells from 1 to 10 mL sample volume up to 10 000× per mL into a small spot inside a disposable millifluidic capture chip. Salmonella typhi, causative agent for typhoid infection has been used to demonstrate the results. Microbes are specifically labeled with antibody‐conjugated magnetic nanoparticles and isolated from bulk sample at 200 μL min⁻¹ flow rate with >90% capture efficiency. Isolated cells are swept to a single spot by decreasing the area under influence of magnetic field and flowing a wash buffer. Using this spot enrichment method, 4 CFU of S. typhi cells enriched from 5 mL sample is detected with turnaround time of less than 1 h.