Self-assembled-monolayer-modified silicon substrate to enhance the sensitivity of peptide detection for AP-MALDI mass spectrometry.
A self-assembled-monolayer-modified silicon substrate was successfully used to enhance the sensitivity of peptide detection for atmospheric pressure-matrix-assisted laser desorption/ionization mass spectrometry (AP-MALDI/MS). The effect of surface modification of silicon wafer samples with NH(2) and OH functional groups was investigated. In addition, solvent effects for the preparation of modified NH(2)-functionalized surfaces were examined. The sensitivities for the two peptides were significantly improved, increasing between 12 and 160 times, for bradykinin and gramicidin, respectively, on an NH(2)-modified silicon surface prepared in toluene, over that on a conventional gold substrate. The limits of detection (LODs) for bradykinin and gramicidin using the conventional gold substrate in AP-MALDI/MS experiments were > 0.011 microM and 110 microM, respectively. Using our SAM approach, the LODs for bradykinin and gramicidin in AP-MALDI/MS can be improved to 0.93 nM and 0.33 microM, respectively. This SAM approach for AP-MALDI/MS is simple and sensitive, and can be used for high-throughput analysis.
Hsieh
Shuchen
S
Department of Chemistry and Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, 70 Lien-Hai Road, Kaohsiung, Taiwan 80424, Republic of China. shsieh@mail.nsysu.edu.tw
Ku
Hsin-Yi
HY
Ke
Yao-Tang
YT
Wu
Hui-Fen
HF
D000577:Amides / Q000032:analysis; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000032:analysis; D001920:Bradykinin / Q000032:analysis; D006096:Gramicidin / Q000032:analysis; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis*; D012825:Silicon / Q000737:chemistry*; D012997:Solvents; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014050:Toluene
D000577:Amides; D000900:Anti-Bacterial Agents; D010455:Peptides; D012997:Solvents; D006096:Gramicidin; D014050:Toluene; D001920:Bradykinin; D012825:Silicon