The lack of functional information and targeted imaging in conventional white-light endoscopy leads to a high miss-rate
of gastrointestinal tumor. The combination of near-infrared fluorescence imaging and endoscopy presents a promising
approach. Here we introduce a new endoscopy method employing a home-made flexible wide-field epi-fluorescence
endoscope, that can be inserted through the biopsy channel of a gastrointestinal endoscope, with the glucose analogue 2-
DeoxyGlucosone as the near-infrared fluorescent probe. System characterization indicates a good sensitivity and
linearity over a large field of view. Its capability of tumor identification and location is demonstrated with in-vivo
imaging of xenografted tumor model.