Significant fluorescence enhancement by supramolecular complex formation between berberine chloride and cucurbit( n = 7)uril and its analytical application

• Published in: Talanta (Oxford) Vol. 84; no. 3; pp. 684 - 689
• Main Authors: Dong, Nan, Cheng, Li-na, Wang, Xiu-lin, Li, Qin, Dai, Chuan-yu, Tao, Zhu
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.05.2011; Elsevier
• Subjects: 1H NMR spectra; Analytical chemistry; Aqueous solutions; Berberine chloride; Berberine determination; Chemistry; Chlorides; Cucurbit( n = 7)uril; Drugs; Exact sciences and technology; Fluorescence; Mathematical analysis; Serums; Spectro-fluorimetry; Spectrometric and optical methods; Supramolecular interaction; Tablets; Urine; Berberine chloride; 1H NMR spectra; Cucurbit( n = 7)uril; Berberine determination; Spectro-fluorimetry; Supramolecular interaction; Cucurbit(n=7)urił; Fluorescence; NMR spectrometry; Selectivity; Fluorescence spectrometry; Molecules; Least squares method; Chlorides; Detection limit; pH; Serum; Tablet; Monitoring; Drug; Urine; Sample; Use; Interference; Association constant; Hydrophobic compound; H NMR spectra; Sensitivity; Isoquinoline; Aqueous solution; Application; Room temperature
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2011.01.071

The supramolecular interaction of cucurbit( n = 7)uril (Q[7]) with berberine chloride (BER) has been studied in aqueous solution at pH 2.0 and room temperature by spectro-fluorimetry. The association constant of the complex was 2.07 × 10 6 L mol −1 calculated by using a nonlinear least squares method. 1H NMR spectra confirmed that a 1:1 stable complex is formed between Q[7] and BER. This work proposes a possible interaction mode, in which the guest BER is incorporated inside the hydrophobic cavity of the host Q[7] via the isoquinoline ring part of the guest molecule. Based on a significant enhancement of the fluorescence intensity of this supramolecular complex, a spectrofluorimetric method with high sensitivity and selectivity has been developed for the determination of BER in aqueous solution in the presence of Q[7]. The linear range of the method was from 7.43 to 11.2 × 10 3 ng mL −1with the detection limit 4.2 ng mL −1. There was no interference from the compounds normally used in tablets, serum or urine constituents. The proposed method was applied to the determination of BER in tablets, serum and urine samples with satisfactory results and good consistency with those obtained by the pharmacopoeia method. This shows that it has promising potential for therapeutic drug monitoring and pharmokinetics and for clinical application.