title: High-performance graphene-titania platform for detection of phosphopeptides in cancer cells.
abstract: Phosphopeptides play a crucial role in many biological processes and constitute some of the most powerful biomarkers in disease detection. However they are often present in very low concentration, which makes their detection highly challenging. Here, we demonstrate the use of a solution-dispersible graphene-titania platform for the selective extraction of phosphopeptides from peptide mixtures. This is followed by direct analysis by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). The efficient charge and energy exchange between graphene and TiO(2) during laser irradiation in SELDI-TOF MS promotes the soft ionization of analytes and affords a detection limit in the attomole range, which is 10(2)-10(5) more sensitive than conventional platforms. The graphene-titania platform can also be used for detecting phosphopeptides in cancer cells (HeLa cells), where it shows high specificity (94%). An expanded library of 967 unique phosphopeptides is detected using significantly reduced loading of extraction matrixes compared to conventional TiO(2) bead-based assays.
authors: Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore.
authors: Lena Ai Ling
authors: LA
authors: Tang
authors: Junzhong
authors: J
authors: Wang
authors: Teck Kwang
authors: TK
authors: Lim
authors: Xuezhi
authors: X
authors: Bi
authors: Wong Cheng
authors: WC
authors: Lee
authors: Qingsong
authors: Q
authors: Lin
authors: Young-Tae
authors: YT
authors: Chang
authors: Chwee Teck
authors: CT
authors: Lim
authors: Kian Ping
authors: KP
authors: Loh
mesh_terms: D019295:Computational Biology; D006108:Graphite / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D007526:Isoelectric Point; D036103:Nanotechnology; D010748:Phosphopeptides / Q000032:analysis*; D012996:Solutions / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014025:Titanium / Q000737:chemistry*; D014357:Trypsin / Q000378:metabolism
chemical_list: D010748:Phosphopeptides; D012996:Solutions; C009495:titanium dioxide; D006108:Graphite; D014025:Titanium; D014357:Trypsin