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

Determination of luteolin based on the gold nanoparticle-catalyzed luminol-HgCl_2 chemiluminescence system

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.