l-Tetramethylammonium-Derived Blue Fluorescent Carbon Dots for Tetracycline Sensing and Memristor Technology

A facile solvothermal strategy employing l-asparagine as the sole carbon–nitrogen precursor was developed for the synthesis of bright blue-emitting carbon dots (B-CDs) with remarkable optical properties. The as-prepared B-CDs exhibit optimal excitation/emission wavelengths at 378 and 466 nm, a notably high quantum yield (QY) of 19.2%, and superior aqueous dispersibility, salt tolerance, and photostability. Leveraging their ultrasensitive response toward tetracycline antibiotics (TET, CTC, and OTC), we engineered a fluorescent nanoprobe enabling quantitative detection with an impressive linear correlation coefficient (R2) of 0.999 and a detection limit down to 0.139 μmol/L. Furthermore, preliminary investigations revealed the exceptional potential of B-CDs as functional materials in memristive devices, demonstrating their unique advantages for advanced electronic applications. This study not only expands the multifunctionality of carbon-based nanomaterials but also provides innovative material platforms for antibiotic surveillance and neuromorphic computing technology.