The invention described herein relates generally to methods, sensors, devices and kits for electrochemical detection of a target analyte in a sample. In certain aspects, the methods, sensors, devices and kits described herein can be used to detect low concentrations of at least one target analyte using small sample volumes. In some embodiments, methods, sensors and kits for detecting a microbe, microbe fragment or released endotoxin in a test sample, including bodily fluids such as blood and tissues of a subject, food, water, and environmental surfaces, are also provided herein.