An Integrated Plasmo-Photoelectronic Nanostructure Biosensor Detects an Infection Biomarker Accompanying Cell Death in Neutrophils

Bacterial infections leading to sepsis are a major cause of deaths in the intensive care unit. Unfortunately, no effective methods are available to capture the early onset of infectious sepsis near the patient with both speed and sensitivity required for timely clinical treatment. To fill the gap, the authors develop a highly miniaturized (2.5 × 2.5 µm²) plasmo-photoelectronic nanostructure device that detected citrullinated histone H3 (CitH3), a biomarker released to the blood circulatory system by neutrophils. Rapidly detecting CitH3 with high sensitivity has the great potential to prevent infections from developing life-threatening septic shock. To this end, the author's device incorporates structurally engineered arrayed hemispherical gold nanoparticles that are functionalized with high-affinity antibodies. A nanoplasmonic resonance shift induces a photoconduction increase in a few-layer molybdenum disulfide (MoS₂) channel, and it provides the sensor signal. The device achieves label-free detection of serum CitH3 with a 5-log dynamic range from 10⁻⁴ to 10¹ ng mL and a sample-to-answer time <20 min. Using this biosensor, the authors longitudinally measure the dynamic CitH3 profiles of individual living mice in a sepsis model at high resolution over 12 hours. The developed biosensor may be poised for future translation to personalized management of systemic bacterial infections.