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Chung-hsuan Chen - One of the best experts on this subject based on the ideXlab platform.

  • Sinapinic Acid clusters distribution from monomer to mega Dalton’s region in MALDI process
    Chemical Physics Letters, 2013
    Co-Authors: Kuang-hua Chang, Chia-lin Wu, Chung-hsuan Chen
    Abstract:

    Abstract In this work, we report the first complete Sinapinic Acid clusters distribution from monomer to mega Dalton’s region by matrix-assisted laser desorption/ionization (MALDI). A decrease of eight orders in intensity was observed from monomer ion to 10 000-mer ion. The results fit to the model of laser ablation induced desorption process with bimodal power-law dependence. In addition, the detailed measurements on the populations of different sizes of clusters can provide some insight of different models of the mechanism for MALDI.

  • Sinapinic Acid clusters distribution from monomer to mega dalton s region in maldi process
    Chemical Physics Letters, 2013
    Co-Authors: Kuang-hua Chang, Chia-lin Wu, Chung-hsuan Chen
    Abstract:

    Abstract In this work, we report the first complete Sinapinic Acid clusters distribution from monomer to mega Dalton’s region by matrix-assisted laser desorption/ionization (MALDI). A decrease of eight orders in intensity was observed from monomer ion to 10 000-mer ion. The results fit to the model of laser ablation induced desorption process with bimodal power-law dependence. In addition, the detailed measurements on the populations of different sizes of clusters can provide some insight of different models of the mechanism for MALDI.

Weilung Tseng - One of the best experts on this subject based on the ideXlab platform.

  • Sinapinic Acid directed synthesis of gold nanoclusters and their application to quantitative matrix assisted laser desorption ionization mass spectrometry
    Nanoscale, 2014
    Co-Authors: Tzuheng Chen, Chengju Yu, Weilung Tseng
    Abstract:

    Core etching of gold nanoparticles (AuNPs) into smaller-sized clusters is a classic method for fabricating gold nanoclusters (AuNCs). The top down-based synthesis of AuNCs includes two steps: (i) reducing the Au3+ precursor solution to generate AuNPs in the presence of protecting ligands and (ii) core etching of the formed AuNPs into the AuNCs via ligand exchange. For the first time, this paper describes a one-step approach for preparing AuNCs using a top down approach. The Sinapinic Acid (SA)-induced formation of the AuNCs involved a three-step reaction process. First, large AuNPs (>200 nm) were quickly formed after mixing SA and the Au3+ precursor solution. Second, excess SA molecules self-assembled on the NP surface, and large AuNPs were etched to small AuNPs via electrostatic repulsion between the neighboring SA molecules. Finally, SA-induced core etching of the AuNPs resulted in the formation of the AuNCs within 70 min. Furthermore, we showed that the presence of the AuNCs in SA was capable of suppressing crystal growth and eliminating the coffee-ring effect. Thus, proteins can be successfully quantified using the SA–AuNCs as matrices for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Compared with using SA as matrices, the SA–AuNCs offered substantial advantages for improving shot-to-shot reproducibility and enhancing the ionization efficiency of proteins.

  • Sinapinic Acid-directed synthesis of gold nanoclusters and their application to quantitative matrix-assisted laser desorption/ionization mass spectrometry.
    Nanoscale, 2014
    Co-Authors: Tzuheng Chen, Chengju Yu, Weilung Tseng
    Abstract:

    Core etching of gold nanoparticles (AuNPs) into smaller-sized clusters is a classic method for fabricating gold nanoclusters (AuNCs). The top down-based synthesis of AuNCs includes two steps: (i) reducing the Au3+ precursor solution to generate AuNPs in the presence of protecting ligands and (ii) core etching of the formed AuNPs into the AuNCs via ligand exchange. For the first time, this paper describes a one-step approach for preparing AuNCs using a top down approach. The Sinapinic Acid (SA)-induced formation of the AuNCs involved a three-step reaction process. First, large AuNPs (>200 nm) were quickly formed after mixing SA and the Au3+ precursor solution. Second, excess SA molecules self-assembled on the NP surface, and large AuNPs were etched to small AuNPs via electrostatic repulsion between the neighboring SA molecules. Finally, SA-induced core etching of the AuNPs resulted in the formation of the AuNCs within 70 min. Furthermore, we showed that the presence of the AuNCs in SA was capable of suppressing crystal growth and eliminating the coffee-ring effect. Thus, proteins can be successfully quantified using the SA–AuNCs as matrices for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Compared with using SA as matrices, the SA–AuNCs offered substantial advantages for improving shot-to-shot reproducibility and enhancing the ionization efficiency of proteins.

Chikung Ni - One of the best experts on this subject based on the ideXlab platform.

  • ion to neutral ratios and thermal proton transfer in matrix assisted laser desorption ionization
    Journal of the American Society for Mass Spectrometry, 2015
    Co-Authors: Ichung Lu, Shangyun Wu, Yuri A Dyakov, Jienlian Chen, Angus Grayweale, Chikung Ni
    Abstract:

    The ion-to-neutral ratios of four commonly used solid matrices, α-cyano-4-hydroxycinnamic Acid (CHCA), 2,5-dihydroxybenzoic Acid (2,5-DHB), Sinapinic Acid (SA), and ferulic Acid (FA) in matrix-assisted laser desorption/ionization (MALDI) at 355 nm are reported. Ions are measured using a time-of-flight mass spectrometer combined with a time-sliced ion imaging detector. Neutrals are measured using a rotatable quadrupole mass spectrometer. The ion-to-neutral ratios of CHCA are three orders of magnitude larger than those of the other matrices at the same laser fluence. The ion-to-neutral ratios predicted using the thermal proton transfer model are similar to the experimental measurements, indicating that thermal proton transfer reactions play a major role in generating ions in ultraviolet-MALDI.

  • Ion-to-Neutral Ratios and Thermal Proton Transfer in Matrix-Assisted Laser Desorption/Ionization
    Journal of the American Society for Mass Spectrometry, 2015
    Co-Authors: Ichung Lu, Shangyun Wu, Yuri A Dyakov, Jienlian Chen, Angus Gray-weale, Chikung Ni
    Abstract:

    The ion-to-neutral ratios of four commonly used solid matrices, α-cyano-4-hydroxycinnamic Acid (CHCA), 2,5-dihydroxybenzoic Acid (2,5-DHB), Sinapinic Acid (SA), and ferulic Acid (FA) in matrix-assisted laser desorption/ionization (MALDI) at 355 nm are reported. Ions are measured using a time-of-flight mass spectrometer combined with a time-sliced ion imaging detector. Neutrals are measured using a rotatable quadrupole mass spectrometer. The ion-to-neutral ratios of CHCA are three orders of magnitude larger than those of the other matrices at the same laser fluence. The ion-to-neutral ratios predicted using the thermal proton transfer model are similar to the experimental measurements, indicating that thermal proton transfer reactions play a major role in generating ions in ultraviolet-MALDI.

Kuang-hua Chang - One of the best experts on this subject based on the ideXlab platform.

  • Sinapinic Acid clusters distribution from monomer to mega Dalton’s region in MALDI process
    Chemical Physics Letters, 2013
    Co-Authors: Kuang-hua Chang, Chia-lin Wu, Chung-hsuan Chen
    Abstract:

    Abstract In this work, we report the first complete Sinapinic Acid clusters distribution from monomer to mega Dalton’s region by matrix-assisted laser desorption/ionization (MALDI). A decrease of eight orders in intensity was observed from monomer ion to 10 000-mer ion. The results fit to the model of laser ablation induced desorption process with bimodal power-law dependence. In addition, the detailed measurements on the populations of different sizes of clusters can provide some insight of different models of the mechanism for MALDI.

  • Sinapinic Acid clusters distribution from monomer to mega dalton s region in maldi process
    Chemical Physics Letters, 2013
    Co-Authors: Kuang-hua Chang, Chia-lin Wu, Chung-hsuan Chen
    Abstract:

    Abstract In this work, we report the first complete Sinapinic Acid clusters distribution from monomer to mega Dalton’s region by matrix-assisted laser desorption/ionization (MALDI). A decrease of eight orders in intensity was observed from monomer ion to 10 000-mer ion. The results fit to the model of laser ablation induced desorption process with bimodal power-law dependence. In addition, the detailed measurements on the populations of different sizes of clusters can provide some insight of different models of the mechanism for MALDI.

Huifen Wu - One of the best experts on this subject based on the ideXlab platform.

  • synthesis of a highly dispersive Sinapinic Acid graphene oxide sa go and its applications as a novel surface assisted laser desorption ionization mass spectrometry for proteomics and pathogenic bacteria biosensing
    Analyst, 2015
    Co-Authors: Hani Nasser Abdelhamid, Huifen Wu
    Abstract:

    Graphene oxide (GO)-modified Sinapinic Acid (3,5-dimethoxy-4-hydroxycinnamic Acid, SA) (SA@GO) was synthesized and characterized; it was then investigated as a new surface assisted laser desorption/ionization mass spectrometry (SALDI-MS) for proteomics and pathogenic bacteria biosensing. SA@GO could effectively decrease the time necessary for sweet spotting searching, reducing the amount of organic matrix and solvent and enhance the sensitivity. SA@GO shows high performance as a matrix alone without the need to add trifluoroacetic Acid (TFA). However, the analysis of the intact bacteria cells shows improvement in the signal intensity (2–5 fold) and offers a low limit of detection. All these analyses could be performed with low concentrations (1–10 fmol) and tiny volumes (0.5–1 μL). This study demonstrated that the exploration of new hybrid materials is pivotal to achieve high performance and high ionization. Because of the plane of GO, it assists protein–protein interactions that make it undergo softer ionization.

  • Synthesis of a highly dispersive Sinapinic Acid@graphene oxide (SA@GO) and its applications as a novel surface assisted laser desorption/ionization mass spectrometry for proteomics and pathogenic bacteria biosensing
    Analyst, 2015
    Co-Authors: Hani Nasser Abdelhamid, Huifen Wu
    Abstract:

    Graphene oxide (GO)-modified Sinapinic Acid (3,5-dimethoxy-4-hydroxycinnamic Acid, SA) (SA@GO) was synthesized and characterized; it was then investigated as a new surface assisted laser desorption/ionization mass spectrometry (SALDI-MS) for proteomics and pathogenic bacteria biosensing. SA@GO could effectively decrease the time necessary for sweet spotting searching, reducing the amount of organic matrix and solvent and enhance the sensitivity. SA@GO shows high performance as a matrix alone without the need to add trifluoroacetic Acid (TFA). However, the analysis of the intact bacteria cells shows improvement in the signal intensity (2–5 fold) and offers a low limit of detection. All these analyses could be performed with low concentrations (1–10 fmol) and tiny volumes (0.5–1 μL). This study demonstrated that the exploration of new hybrid materials is pivotal to achieve high performance and high ionization. Because of the plane of GO, it assists protein–protein interactions that make it undergo softer ionization.