This study presents a reversible, mediatorless, near-infrared glucose sensor based on glucose oxidase-wrapped SWCNTs. A combination of fluorescence, absorption, and Raman spectroscopy measurements suggest a fluorescence enhancement mechanism based on localized enzymatic doping of SWCNT defect sites that does not rely on added mediators. The cyclic addition and removal of glucose is shown to enhance and recover fluorescence, demonstrating reversibility.