基于纳米金催化鲁米诺-氯化汞化学发光新体系测定木犀草素

目的: 基于纳米金对鲁米诺-氯化汞化学发光体系有良好的催化作用,建立测定木犀草素含量的高灵敏流动注射-化学发光分析法。 方法: 采用流动注射技术,实验研究了影响化学发光的各种因素;根据体系的化学发光光谱和紫外-可见吸收光谱结果,探讨了可能的化学发光机理。 结果: 0.1 mol·L^-1 氢氧化钠、4.0×10^-4 mol·L^-1鲁米诺、6.08×10^-5 mol·L^-1纳米金与1.0×10^-3 mol·L^-1 HgCl₂组成最优的化学发光体系。在优化的实验条件下,本方法测定木犀草素的线性范围为2.0×10^-9~1.0×10^-7 g·mL^-1(r=0.9929),检出限为1.5×10^-9 g·mL^-1,RSD为2.1%(C=1.0×10^-8 g·mL^-1,n=11)。纳米金作为电子转移的媒介,在鲁米诺-氯化汞反应过程中起催化作用;木犀草素和鲁米诺竞争与氯化汞发生反应,抑制了鲁米诺氧化成鲁米诺自由基,导致发光强度的降低。 结论: 利用本法成功地测定了血清与合成样品中木犀草素的含量。

Objective: To establish a highly sensitive flow injection-chemiluminescence(CL) method for the determination of luteolin,based on the good catalysis effect of gold nanoparticles(AuNPs) for the luminol-HgCl₂ CL system. Method: The various factors were optimized to obtain the maximum CL intensity of luteolin.The possible CL mechanism of AuNPs catalyzed luminol-HgCl₂-luteolin reaction has been proposed according to the UV-visible absorption and CL spectra. Results: The optimal CL system consisted of 0.1 mol·L^-1 NaOH,4.0×10^-4 mol·L^-1 luminol,6.08×10^-5 mol·L^-1 AuNPs and 1.0×10^-3 mol·L^-1 HgCl₂.Under the selected experimental conditions,the linear range was 2.0×10^-9-1.0×10^-7 g·mL^-1(r=0.9929)with the detection limit of 1.5×10^-9 g·mL^-1.The relative standard deviation(RSD) was 2.1% for 1.0×10^-8 g·mL^-1 luteolin(n=11).The CL enhancement by AuNPs of the luminol-HgCl₂ system was supposed to originate from the catalysis of AuNPs,which facilitated the radical generation and electron-transfer processes taking place on the surface of AuNPs.Luteolin was found to inhibit the CL intensity of AuNPs catalyzed luminol-HgCl₂ system due to its competition with luminol for active oxygen intermediates. Conclusion: The proposed method is successfully applied to the determination of luteolin in serum and synthetic samples.