[1] [1] TALHOUT R,NOBELEN S V D,KIENHUIS A S.An inventory of methods suitable to assess additive-induced characterising flavours of tobacco products ［J］.Drug Alcohol Depe,2016,161,9.

[2] [2] STEPANOV I,BIENER L,YERSHOVA K,et al.Monitoring tobacco-specific n-nitrosamines and nicotine in novel smokeless tobacco products:findings from round ii of the new product watch［J］.Nicotine Tob Res,2014,16(8):1070.

[9] [9] OTTO A,Top Appl Phys［J］,1984,54:289.

[10] [10] MOSKOVITS M,Rev Mod Phys［J］,1985,3:783.

[17] [17] LI J F,ZHANG Y J,DING S Y,et al.Core–shell nanoparticle-enhanced Raman spectroscopy ［J］.Chem Rev,2017,7:5002.

[18] [18] FRENS G,Controlled nucleation for the regulation of the particle size in monodisperse gold suspensions ［J］.Nat Phys Sci,1973,1:20.

[19] [19] LI Y J,HUANG W J,SUN S G.A universal approach for the self-assembly of hydrophilic nanoparticles into ordered monolayer films at a toluene/water interface［J］.Angew Chem,2010,45(16):2537.

[20] [20] DUAN H W,WANG D Y,KURTH D G,et al.Directing self-assembly of nanoparticles at water/oil interfaces［J］.Angew Chem Int Edit,2004,43(42):5639.

[21] [21] LIU B,BLASZCZYK A,MAYOR M,et al.Redox-switching in a viologen-type adlayer:an electrochemical shell-isolated nanoparticle enhanced Raman spectroscopy study on au(111)-(1×1) single crystal electrodes［J］.ACS Nano,2011,5(7):5662.