ABSTRACT UV–vis spectroscopy is widely used for concentration quantification. However, due to light scattering and inner‐filter effects, the accuracy is severely compromised for optically challenging media, such as highly concentrated, turbid, or fluorescent samples. To address these challenges, a highly light‐sensitive self‐powered sensing (SPS) platform is developed by integrating a bicontinuous network (BN) photoelectrocatalyst toward oxygen reduction reaction (ORR) into a zinc‐air battery (ZAB), termed BN‐SPS. The reversible and intensity‐dependent response under illumination of the ORR performance enables the ZAB to serve as a light‐responsive power source and sensor. Leveraging this dual functionality, we devise a detection strategy that adjusts the effective optical path length by varying the thickness of the sample layer (like “solution filter”)—a key innovation for handling samples across a wide concentration range. Critically, the open‐circuit voltage of the BN‐SPS shows a strong linear correlation with analyte concentration and turbidity, allowing accurate quantification of otherwise challenging samples. Remarkably, the upper detection limits surpass those of conventional UV–vis spectroscopy by factors of 200, 50, 8, and 5 for KMnO 4 , Rhodamine B, turbidity, and ammonia, respectively. This work represents a significant breakthrough in self‐powered electrochemical sensing and substantially expands the scope of reliable quantitative analysis in optically challenging media.
Long et al. (Mon,) studied this question.