DIOS mass spectrometry

W. G. Lewis, Z. Shen, M. G. Finn, and G. Siuzdak. Desorption/Ionization On Silicon (DIOS) Mass Spectrometry Background and Applications. Int. J. Mass Spectrom., 226(2003) 107-116. 

Lewis, W.G., Shen, Z., Finn, M.G., Siudzak, G. Desorption/ionization on silicon (DIOS) mass spectrometry background and applications. Int. ]. Mass Spectrom. 2003, 226, 107-116. 

Law KP (2010) Laser desorption/ionization mass spectrometry on nanostructured semiconductor substrates DIOS (TM) and QuickMass (TM). Int J Mass Spectrom 290 72-84 Law KP, Larkin JR (2011) Recent advances in SALDI-MS techniques and their chemical and bioanalytical applications. Anal Bioanal Chem 399 2597-2622 Lewis WG, Shen Z, Finn MG, Siuzdak G (2003) Desorption/ionization on silicon (DIOS) mass spectrometry background and applications. Int J Mass Spectrom 226 107-116 Li Q, Alonso R, Renner SA, Winefordner JD, Powell DH (2005) Desorption/ionization on porous silicon mass spectrometry studies on pentose-borate complexes. Anal Chem 77 4503-4508 Lin Z, Zhang S, Zhao M, Yang C, Chen D, Zhang X (2008) Rapid screening of clenbuterol in urine samples by desorption electrospray ionization tandem mass spectrometry. Rapid Commun Mass Spectrom 22 1882-1888... 

Xiao Y, Retterer ST, Thomas DK, Tao J-Y, He L (2009) Impaets of surface morphology on ion desorption and ionization in desorption ionization on porous silicon (DIOS) mass spectrometry. J Phys Chem C 113 3076-3083... 

Liu, Q., He, L. (2008) Semi-quantitative study of solvent and surfece effects on analyte ionization in desorption ionization on silicon (DIOS) mass spectrometry. J Am Soc Mass Spectrom, 19, 8-13. 

DGE a AC AMS APCI API AP-MALDI APPI ASAP BIRD c CAD CE CF CF-FAB Cl CID cw CZE Da DAPCI DART DC DE DESI DIOS DTIMS EC ECD El ELDI EM ESI ETD eV f FAB FAIMS FD FI FT FTICR two-dimensional gel electrophoresis atto, 10 18 alternating current accelerator mass spectrometry atmospheric pressure chemical ionization atmospheric pressure ionization atmospheric pressure matrix-assisted laser desorption/ionization atmospheric pressure photoionization atmospheric-pressure solids analysis probe blackbody infrared radiative dissociation centi, 10-2 collision-activated dissociation capillary electrophoresis continuous flow continuous flow fast atom bombardment chemical ionization collision-induced dissociation continuous wave capillary zone electrophoresis dalton desorption atmospheric pressure chemical ionization direct analysis in real time direct current delayed extraction desorption electrospray ionization desorption/ionization on silicon drift tube ion mobility spectrometry electrochromatography electron capture dissociation electron ionization electrospray-assisted laser desorption/ionization electron multiplier electrospray ionization electron transfer dissociation electron volt femto, 1CT15 fast atom bombardment field asymmetric waveform ion mobility spectrometry field desorption field ionization Fourier transform Fourier transform ion cyclotron resonance... 

G. A mass spectrometry plate reader monitoring enzyme activity and inhibition with a desorption/ ionization on silicon (DIOS) platform. ChemBioChem 2004, 5, 921-927. 

The ether was concentrated by Kudema- Danish evaporation and then solvent exchanged to hexane to give a final volume of 0.3-0.4 mL. To quantify the compounds present, the samples were spiked with a known amount of anthracene-dio as an internal standard just prior to injection. The concentrated extracts were analyzed by capillary GC-mass spectrometry (GC-MS). 

Wall, D. B., Finch, J. W., and Cohen, S. A. (2004). Comparison of desorption/ionization on silicon (DIOS) time-of-flight and liquid chromatography/tandem mass spectrometry for assaying enzyme-inhibition reactions. Rapid Commun. Mass Spectrom. 18 1482-1486. 

A continuous improvement has allowed analysis to reach detection limits at the pico-, femto- and attomole levels [72,73], Furthermore, the direct coupling of chromatographic techniques with mass spectrometry has improved these limits to the atto- and zeptomole levels [74,75], A sensitivity record obtained by mass spectrometry has been demonstrated by using modified desorption/ionization on silicon DIOS method to measure concentration of a peptide in solution. This technique has achieved a lower detection limit of 800 yoctomoles, which corresponds to about 480 molecules [76]. 

Thomas JJ, Shen Z, Crowell JE, Finn MG, Siuzdak G (2001) Desorption/ionization on silicon (DIOS) a diverse mass spectrometry platform for protein characterization. Proc Natl Acad Sci 98 4932-4937... 

Desorption/lonization on Silicon Mass Spectrometry (DIOS-MS)... 

Fig. 16.19. Mass spectrometry of WIN antiviral drug, (a) DIOS-MS spectrum ofWIN deposited upon porous silicon. Inset DIOS-PSD-MS spectrum of WIN. (b) MALDI-MS spectrum of WIN dispersed in a-cyano-4-hydroxycinnamic acid (HCCA). (c) Attempted...

Random nanopillars can also be utilized in chemical microsystems [10]. Intensity of desorp-tion/ionization on silicon mass spectrometry (DIOS-MS) is dependent on surface area. At first DIOS plate material was porous silicon, but it has been shown that using nanopillars instead of porous silicon, signal intensity can be increased. 

Siuzdak and coworkers have recently introduced another nanoscale methodology which advances the capabilities of desorption/ionization mass spectrometry, termed nanostructure initiator mass spectrometry (NIMS) [51]. NIMS consists of a nanostructured surface composed of roughly 10-nm pores with initiator materials such as fluorinated siloxanes embedded within the structure. The analyte is adsorbed to the NIMS surface. Subsequent laser irradiation results in a rapid surface heating that causes the initiator to vaporize from the clathrates, which in turn desorbs the analyte [51]. This approach allows the analysis not only of small molecules but also of large molecules, including peptides and proteins, unlike DIOS-MS. The device used for sample preparation via spray deposition, as weU as representative spectra of vitamin D3 and testosterone, are shown in Figure 9.4 [52]. 

Despite the successful application of MALDl and DIOS in the analysis of LMM compounds, the analysis remains a challenge. This stems primarily from low ionization efficiencies due to a lack of functional groups with high proton affinity, matrix suppression effects, isobaric overlay of the matrix with the analyte, and the high volatility of many analytes. One approach to improve the analysis of LMM compounds is by derivatization. The derivatization of samples prior to MS analysis has been widely employed in gas chromatography-mass spectrometry (GC-MS)... 

Thomas, J.J., Shen, Z., Crowell, J.E., Finn, M.G., Siuzdak, G. (2001) Desorp-tion/Ionization on Silicon (DIOS) A Diverse Mass Spectrometry Platform for Protein Characterization. Proc. Natl. Acad. Sci. USA 98 4932-4937. 

Figure 3.11 summarizes such key experimental points. As a first point, we have to choose the appropriate ionization method for the detection of small metabolites, we have alternative choices other than MALDI, such as secondary ion mass spectrometry (SIMS) [15], nanostructure-initiator mass spectrometry (NIMS) [20,21], desorption/ionization on silicon (DIOS) [22], nanoparticle-assisted laser desorptiopn/ ionization (nano-PALDI) [23], and even laser desorption/ionization (LDI) [24,25]. We consider that MALDI is stiU the most versatile method, particularly due to the soft ionization capability of intact analyte. However, other methods each have unique advantages for example, SIMS and nano-PALDI have achieved higher spatial resolution than conventional MALDI-IMS, and above aU, these mentioned alternative methods are all matrix-free methods, and thus can exclude the interruption of the matrix cluster ion. Next, if MALDI is chosen, experimenters should choose a suitable matrix compound, solvent composition, and further matrix application method for their target analyte. All these factors are critical to obtain sufficient sensitivity because they affect efficiency of analyte extraction, condition of cocrystallization, and, above all, analyte-ionization efficiency. In addition, based on the charge state of the analyte molecule, suitable MS polarity (i.e., positive/ negative ion detection mode) should be used in MS measurement. Below, we shall describe the key experimental points for MALDI-IMS applications of representative metabolites. 

Law, K.P. (2010) Laser desorption/ionization mass spectrometry on nanostructured semiconductor substrates DIOS and QuickMass . International Journal of Mass Spectrometry, 290,72-84. 

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