Aggregation-induced emission enhancement N, S-CQDs for selective detection of CIP in the environment.

Carbon quantum dots (CQDs) have been extensively researched as fluorescent probes, but there are few reports on fluorescence-enhanced probes. Herein, nitrogen and sulfur co-doped CQDs (N, S-CQDs) with blue aggregation-induced emission enhancement (AIEE) fluorescence were synthesized by a one-step hydrothermal reaction. N, S-CQDs can rely on the presence of -OH, C=O, -NH2, and ether bonds on their surfaces and the formation of hydrogen bonds by ciprofloxacin (CIP) containing Ar-F and -COOH functional groups to achieve effective charge transfer. In addition, CIP forces N, S-CQDs to aggregate to form cross-linked structures, which effectively limits the vibration and rotation of N, S-CQDs, leading to enhanced fluorescence of N, S-CQDs. Based on the above intermolecular charge transfer and AIEE between N, S-CQDs and CIP, an efficient and sensitive nano fluorescent probe for the detection of CIP in real water samples was developed, which can achieve sensitive detection of 3.33 × 10-8-1.13 × 10-6M CIP.

[The IR spectra of complexes of fiber containing amidoxime groups with Fe(III), Co(II), Ni(II), Cd(II) and Hg(II)].

By the reaction Fe3+, Co2+, Ni2+, Cd2+ and Hg2+ with fiber containing amidoxime groups modified polyacrylonitrile fiber (AOCF), a series of coordinate complexes-AOCF-Fe(III), AOCF-Co(II), AOCF-Ni(II), AOCF-Cd(II) and AOCF-Hg(II) were prepared in acid medium. The fibers containing amidoxime groups with and without metal ions were taken for FTIR in the range of 4000-400 cm(-1). Their major bonds were assigned and compared. The results showed that in all complexes some bands (vC-N, vC=N and vN-O) were strengthened and a certain shift to higher wave number took place in the FTIR spectra with 4-21 cm(-1) shifts observed. The amidoxime groups and metal ions were bonding with coordinated bond.