title: Evaluation of nanoporous gold with controlled surface structures for laser desorption ionization (LDI) analysis: surface area versus LDI signal intensity.
abstract: The structural effect of a nanoporous gold (NPG) surface on the signal intensities of laser desorption ionization-mass spectrometry (LDI-MS) were investigated using NPG surfaces with controlled structures. The relationship between surface area and LDI efficiency was compared and evaluated. Comparisons between bare flat gold and NPG surfaces show that nanostructures increased LDI efficiency. We also found that the LDI signal decreased with increasing depth of nanoporous layers, thus increasing the surface area. This result agrees with a previous report (Shin J. A. et al., J. Am. Soc. Mass Spectrom. 2010, 21, 989) in which the LDI efficiency of small molecules decreased for ZnO wires with longer lengths. This observation was explained by the penetration and deposition of samples into locations inaccessible to photons because of structural screening. The LDI-MS analysis of oils with NPG surfaces (but without matrix) showed the same trend whereby the NPG with about a 200 nm depth of porous area showed the highest sensitivity. This study clearly shows that the active surface area for solution chemistry can differ from LDI-MS and that NPGs can function as a substrate for LDI oil analysis.
authors: Department of Chemistry, Kyungpook National University, Daegu, Korea.
authors: Jang Mi
authors: JM
authors: Jin
authors: Suhee
authors: S
authors: Choi
authors: Young Hwan
authors: YH
authors: Kim
authors: Man Ho
authors: MH
authors: Choi
authors: Jongwon
authors: J
authors: Kim
authors: Sunghwan
authors: S
authors: Kim
mesh_terms: D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D058608:Nanopores; D010578:Petroleum; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014700:Verapamil / Q000737:chemistry
chemical_list: D010578:Petroleum; D006046:Gold; D014700:Verapamil