Protea Biosciences. Inc. | Date: 2011-05-17
Morris N.J.,Protea Biosciences Inc. |
Anderson H.,Protea Biosciences Inc. |
Thibeault B.,University of California at Santa Barbara |
Vertes A.,George Washington University |
And 2 more authors.
Deep UV projection lithography (DUV-PL) and deep reactive ion etching (DRIE) processes are used to fabricate silicon nanopost surfaces for laser desorption ionization mass spectrometry (LDI-MS). Described here is a fabrication process that is amenable to mass production of silicon nanopost array (NAPA) devices optimized for laser desorption ionization mass spectrometry of small molecules less than 2 kDa, suitable for pharmaceutical and metabolomics applications. The resulting devices exhibit excellent performance for analysis and quantitation of pharmaceutical drugs over at least four orders of magnitude dynamic range, with very good limits of detection and lower limits of quantitation. For metabolite analysis, these devices also exhibit improved spectral quality over MALDI-MS which suffers from noise from the chemical matrix. With the ability to perform a one-step sample spotting, these devices become extremely useful for high throughput workflows afforded by MALDI mass spectrometry platforms. © 2015 The Royal Society of Chemistry. Source
Stopka S.A.,George Washington University |
Rong C.,George Washington University |
Korte A.R.,George Washington University |
Yadavilli S.,Research Center for Genetic Medicine |
And 4 more authors.
Angewandte Chemie - International Edition
Mass spectrometry imaging (MSI) is a comprehensive tool for the analysis of a wide range of biomolecules. The mainstream method for molecular MSI is matrix-assisted laser desorption ionization, however, the presence of a matrix results in spectral interferences and the suppression of some analyte ions. Herein we demonstrate a new matrix-free MSI technique using nanophotonic ionization based on laser desorption ionization (LDI) from a highly uniform silicon nanopost array (NAPA). In mouse brain and kidney tissue sections, the distributions of over 80 putatively annotated molecular species are determined with 40 μm spatial resolution. Furthermore, NAPA-LDI-MS is used to selectively analyze metabolites and lipids from sparsely distributed algal cells and the lamellipodia of human hepatocytes. Our results open the door for matrix-free MSI of tissue sections and small cell populations by nanophotonic ionization. Weight and see: A matrix-free mass spectrometry imaging technique uses nanophotonic ionization based on laser desorption ionization from a highly uniform silicon nanopost array. In mouse-brain and kidney tissue sections, the distributions of over 80 molecular species could be determined with 40 μm spatial resolution. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source
Deimler R.E.,West Virginia University |
Razunguzwa T.T.,Protea Biosciences Inc. |
Reschke B.R.,Protea Biosciences Inc. |
Walsh C.M.,Protea Biosciences Inc. |
And 2 more authors.
Laser ablation electrospray ionization tandem mass spectrometry (LAESI-MS/MS) was applied to the analysis of scheduled drugs in a variety of forensically relevant media including solutions, hair and botanic matter. LAESI-MS/MS was generally able to identify unreacted drugs directly from solutions in which common presumptive color tests had been performed. A significant correlation of 0.7 was found between the pKa of the drugs and the frequency of a positive identification in the solutions indicating that basic drugs are more favorably ionized. Basic drugs like amphetamine and methamphetamine were readily identified at 0.01 mg mL-1, well below the normal limits of detection of the color test results. For hair analysis, LAESI-MS/MS could directly identify the presence of morphine, codeine and cocaine in human hair samples at biologically relevant levels of ∼10 ng mg-1 of drug in hair. This detection was possible without any hydrolysis, extraction, derivatization, or separation of the drugs. LAESI-MS/MS could also identify the presence of tetrahydrocannabinol (THC) or cannabidiol (CBD) in cannabis leaves, in addition to mapping the spatial abundance of THC/CBD across the different leaves. The simplicity and lack of sample preparation for hair and plant analyses are noteworthy benefits, but the current detection limits are close to biologically relevant levels. These preliminary studies indicate that with some additional optimization and validation, LAESI-MS/MS could provide a direct confirmation of color spot test results at an average analysis time of 20 seconds per sample, which is considerably faster than any GC or LC run and could be a major benefit for large caseloads or backlog reduction. © the Partner Organisations 2014. Source