Annually in the United States there are approximately 750,000 cases of sepsis resulting in 200,000 deaths [1]. Since it is difficult to counter the effects of endotoxin, many medical experts suggest that the best way to prevent endotoxin-induced sepsis is a rigorous endotoxin screening process [2,3]. The proposed research seeks to enable development of a low-cost, hence widely available, highly sensitive and rapid endotoxin detection system based on the use of disposable remote-query magnetoelastic sensors. Utilizing the viscosity-monitoring capabilities of the magnetoelastic sensor platform, this system determines the endotoxin level by measuring the gel formation in Limulus Amoebocyte Lysate (LAL) assay, a popular assay derived from horseshoe crabs for endotoxin quantification. The miniature nature of the sensor, coupled with its excellent viscosity sensitivity, enables micro-Liter assays significantly reducing cost and facilitating ease of use. We believe that the proposed system will significantly reduce the rate of sepsis mortality by allowing healthcare providers to easily, rapidly, and inexpensively detect endotoxic infections in high-risk patients. Passive, ribbon-like magnetoelastic sensors, immersed within the LAL assay-test solution, are remotely interrogated via magnetic fields. Preliminary studies have shown that the resonance amplitude of the magnetoelastic sensor decreases during the coagulation of the LAL assay, and the magnitude of the time rate of change is proportional to the endotoxin concentration. The focus of this effort is to conduct the enabling science and engineering that will facilitate development of the magnetoelastic endotoxin detection device and optimize its performance. Specifically, over the two year project duration we will: {1} further miniaturize and optimize the sensors to reduce the amount of LAL assay needed with enhanced sensitivity. {2} refine the needed sensor reader electronics, extending the upper frequency operational limit and including an additional 40dB of gain. {3} develop a technique and/or algorithm to accurately calculate the endotoxin level based on the initial response of the sensor to enable endotoxin quantification in but a few minutes time. {4} Design and fabricate the pyrogen-free LAL-mixing disposable package for the sensor and the sample collection apparatus. We seek to significantly reduce the rate of sepsis mortality by providing healthcare providers an accurate, inexpensive, and rapid tool for detecting endotoxic infections in at-risk patients. Considering the annual mortality rate due to sepsis, over 200,000 deaths, we believe the success of this project will make a significant contribution in improving public health. ? ? ?
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