Sensitive detection of amoxicillin in aqueous solution with novel fluorescent probes containing boron-doped carbon quantum dots

The antibiotic amoxicillin (AMX) was detected sensitively by a novel fluorescence probes composed with boron-doped carbon quantum dots (B-CQDs). B-CQDs with a 5:1 molar ratio of C atom versus B atom can be synthesized first by mixing citric acid with boric acid as a B source on suitable hydropyrolysis condition. The AMX in an aqueous solution was detected via fluorometry. Results showed that the as-prepared B-CQDs had nattier blue fluorescence, a narrow diameter range, a mean particle size of 2.3 nm, a multigraphite phase structure, and a quantum yield of 30.85%. The B-CQDs as probes can sensitively detect AMX in aqueous solution, and the fluorescence signal of the B-CQDs-AMX system was strengthened linearly with the increase in AMX concentration when in the antibiotic concentration range of 1.43–429.12 μmol·L−1 with limit of detection of 0.825 μmol·L−1. B-CQDs detected AMX mechanism as follows: the probes can be combined with antibiotic via primary hydrogen bond between them, and their combining abilities were enhanced by increasing the temperature of this sensing system in the range of 288–313 K.