<![CDATA[The effective clinical management of bladder cancer is heavily contingent upon frequent surveillance due to its high recurrence rate. However, conventional diagnostic modalities, such as cystoscopy and urine cytology, remain constrained by invasiveness, high procedural costs, or insufficient sensitivity, particularly for early-stage detection. To address these limitations, this study presents a rigorous diagnostic performance evaluation of a customdeveloped, low-cost portable fluorometer based on the fluorescence quenching of Carbon Quantum Dots (CQDs) conjugated with anti-47 kDa antibodies. A comparative cross-sectional study was conducted involving 20 clinical urine samples, comprising histopathologically confirmed positive cases and healthy controls, measured via an integrated AS-7341 spectral sensor system targeting the 515 nm emission channel. The statistical validity of the proposed device was assessed using a comprehensive nonparametric framework. The ann- Whitney U test demonstrated a statistically significant difference in fluorescence intensity between the cohorts (p < 0.05), validating the biochemical detection mechanism. Furthermore, Receiver Operating Characteristic (ROC) analysis revealed a robust discriminatory capability with an Area Under the Curve (AUC) of 0.835. Through the maximization of the Youden Index (J=0.7), an optimal intensity cut-off point was established at 3598.6 a.u., yielding a sensitivity of 90% and a specificity of 80%. These findings conclusively demonstrate the potential of the system as a high- precision, non-invasive pre-screening tool suitable for deployment in resource-limited healthcare settings. Keywords: Bladder Cancer, Fluorescence Quenching, Fluorometer Portable, Nonparametric Test, ROC Analysis ]]>
