title: A nano-patterned self assembled monolayer (SAM) rutile titania cancer chip for rapid, low cost, highly sensitive, direct cancer analysis in MALDI-MS.
abstract: We developed a cancer chip by nano-patterning a highly sensitive SAM titanium surface capable of capturing and sensing concentrations as low as 10 cancer cells/mL from the environment by Matrix Assisted Laser Desorption and Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS). The current approach evades any form of pretreatment and sample preparation processes; it is time saving and does not require the (expensive) conventional MALDI target plate. The home made aluminium (Al) target holder cost, on which we loaded the cancer chips for MALDI-TOF MS analysis, is about 60 USD. While the conventional stainless steel MALDI target plate is more than 700 USD. The SAM surface was an effective platform leading to on-chip direct MALDI-MS detection of cancer cells. We compared the functionality of this chip with the unmodified titanium surfaces and thermally oxidized (TO) titanium surfaces. The lowest detectable concentration of the TO chip was 10(3) cells/mL, while the lowest detectable concentration of the control or unmodified titanium chips was 10(6) cells/mL. Compared to the control surface, the SAM cancer chip showed 100,000 times of enhanced sensitivity and compared with the TO chip, 1000 times of increased sensitivity. The high sensitivity of the SAM surfaces is attributed to the presence of the rutile SAM, surface roughness and surface wettability as confirmed by AFM, XRD, contact angle microscope and FE-SEM. This study opens a new avenue for the potent application of the SAM cancer chip for direct cancer diagnosis by MALDI-TOF MS in the near future.
authors.affiliation: Department of Chemistry, National Sun Yat-Sen University, Kaohsiung 70, Lien-Hai Road, Kaohsiung 80424, Taiwan; Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung 70, Lien-Hai Road, Kaohsiung 80424, Taiwan.
authors.forename: M
authors.initials: M
authors.lastname: Manikandan
authors.affiliation: Department of Chemistry, National Sun Yat-Sen University, Kaohsiung 70, Lien-Hai Road, Kaohsiung 80424, Taiwan; Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung 70, Lien-Hai Road, Kaohsiung 80424, Taiwan.
authors.forename: Judy
authors.initials: J
authors.lastname: Gopal
authors.affiliation: Department of Chemistry, National Sun Yat-Sen University, Kaohsiung 70, Lien-Hai Road, Kaohsiung 80424, Taiwan.
authors.forename: Nazim
authors.initials: N
authors.lastname: Hasan
authors.affiliation: Department of Chemistry, National Sun Yat-Sen University, Kaohsiung 70, Lien-Hai Road, Kaohsiung 80424, Taiwan; Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung 70, Lien-Hai Road, Kaohsiung 80424, Taiwan; Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung 70, Lien-Hai Road, Kaohsiung 80424, Taiwan; School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 800, Taiwan; Institute of Medical Science and Technology, National Sun Yat-Sen University, Lien-Hai Road, Kaohsiung 80424, Taiwan. Electronic address: hwu@faculty.nsysu.edu.tw.
authors.forename: Hui-Fen
authors.initials: HF
authors.lastname: Wu
mesh_terms: D015374:Biosensing Techniques; D006801:Humans; D018625:Microscopy, Atomic Force; D009369:Neoplasms / Q000737:chemistry* / Q000473:pathology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation* / Q000379:methods*; D014025:Titanium / Q000737:chemistry*; D014407:Tumor Cells, Cultured; D014961:X-Ray Diffraction
chemical_list: C009495:titanium dioxide; D014025:Titanium
keywords: Cancer chip; Mass spectrometry; Neuro 2A cells; SAM; Thermally oxidized; Titanium