Ultra-sensitivity real-time water pollution detection based on non-Hermitian topolectrical circuit

Ultra-sensitivity water pollution detection is the key to ensuring clean and safe management of water resources. However, most existing high-sensitivity water pollution detection systems rely on expensive and bulky laboratory equipment, which makes the systems non-portable. Meanwhile, most reported portable detection systems cannot meet the requirements for sensitivity and robustness in complex environments. These limitations hinder the implementation of portable high-sensitivity water pollution detection, especially in resource-poor and severely polluted water environments. Here, we developed a water pollution detection approach based on absorbance measurement, enhanced by non-Hermitian topolectrical circuits to improve sensitivity, and enable real-time detection, with promising prospects for future development into a portable system. Experimental results show that the optical absorption detection limit of this system is below 10^-4a.u., enabling the system to rapidly detect 0.1 μg/L methyl violet. Moreover, the response time of this system can reach 15 ms and is suitable for real-time detection of various types of pollutants, whether inorganic, organic, or low concentration microorganisms, with detection concentrations (<1 μg/L) far below the corresponding pollutant emissions or eutrophication standards. Furthermore, incorporating the robustness of topolectrical circuits, the system detection stability has been notably improved, offering broad application prospects in complex environments.