Extending lipoarabinomannan detection limitations with plasmonic gratings

Tuberculosis (TB) is a growing threat that endangers the lives of more than 9.6 million people each year. The early diagnosis and treatment of this disease are critical to preventing serious infections and death. However, accurately diagnosing adults and children in resource-poor regions has proven very difficult. We have developed an ultrasensitive plasmonic grating platform that can detect lipoarabinomannan (LAM), a biomarker for active TB, at concentrations much lower (1 fg/mL range) than currently available sensors by counting single molecules from epifluorescence microscope images. This platform could be used in conventional equipment such as microscopes and microplate readers to aid in the early detection of TB and ultimately the prompt treatment of the disease.