Monitoring and Analysis of Total Tetracyclines in Water from Different Environmental Scenarios Using a Designed Broad-Spectrum Aptamer

Tetracyclines (TCs) are widely present in the environment with extreme toxicity, low concentrations, coexistence with a variety of pollutants, and similarity in their individual molecular structures and toxicology. These challenges make it difficult to analyze and monitor TCs as a class of molecules simultaneously. In this study, a broad-spectrum aptamer capable of recognizing TCs was developed by artificially editing a single-specific aptamer. Subsequently, based on the mathematical proof of broad-spectrum aptamer detection of TCs, an electrochemical sensor was constructed to enable simple and rapid monitoring of TCs with high sensitivity, high selectivity, and a wide detection range. The sensor exhibits a detection range of 0.01 to 1000 nM and a detection limit of 1.18 pM, while maintaining excellent selectivity even in the presence of interfering substances at concentrations up to 100 times the test concentration. This sensor is suitable for quantifying the overall level of TCs in various environmental scenarios, facilitating the study of TCs transport and transformation processes in environmental systems. Finally, the broad-spectrum recognition mechanism of the aptamer was elucidated, which makes the method rational and universal, and will help future researchers to obtain broad-spectrum aptamers for rapid monitoring and analysis of multiple classes of pollutants.