Dual channel detection of tetracycline using room-temperature phosphorescent carbon dots

Excessively employing tetracycline (TC) or even abusing has led to severe environmental pollution and health risks, and monitoring its amount and related residue is of great importance. Although fluorescent carbon dots (CDs) have been employed to detect TC, single-fluorescence detection usually shows the deficiencies of the limited interference resistance and relatively narrow detection range. This study introduced a dual-channel method based on nitrogen-doped phosphorescent carbon dots (N-CDs). By capitalizing on the synergistic effects of fluorescence and phosphorescence signals, this approach effectively improved the detection sensitivity and the linear range. This N-CDs were synthesized through a one-step microwave-assisted method using guanidinopropionic acid and amidinothiourea as the precursors. The findings revealed that TC selectively quenched both the fluorescent and phosphorescent signals of N-CDs mainly based on the inner filter effect (IFE). These finding not only validated the theoretical basis of the dual-channel detection approach but also highlighted its practical potential. The developed method provided a sensitive and reliable technique for detecting TC in various samples and demonstrated the versatility of N-CDs as the promising sensing materials.