The ball lens translates and rotates internally to perform chemical signal mapping. In this image, the x-axis represents the rotational angle (0–360°), and the y-axis represents the translational position (0–30 mm). This mapping enables identification of the specific regions on the catheter surface that interact with cancer biomarkers. Detection of analytes from extracted biofluids, such as urinalysis for bladder cancer biomarkers, remains challenging due to sample dilution and instability outside the human body. This project aims to overcome these limitations by developing a chemical imaging tool that enhances sensor sensitivity through the detection of localized biomarkers in situ. We demonstrated that a nanosensor-functionalized catheter, equipped with a rotating ball lens, can chemically image porcine bladders and detect NMP-22 at a local concentration of 84 nM.