INSTM and Chemistry for Technologies Laboratory, Mechanical and Industrial Engineering Department (DIMI), University of Brescia, via Branze 38, 25123 Brescia, Italy.
INSTM and Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
Sci Rep. 2016 Oct 4;6:34521. doi: 10.1038/srep34521.
SiO/TiO core/shell (T-rex) beads were exploited as "all-in-one" building-block materials to create analytical assays that combine plasmon-free surface enhanced Raman scattering (SERS) and surface assisted laser desorption/ionization (SALDI) mass spectrometry (RaMassays). Such a multi-modal approach relies on the unique optical properties of T-rex beads, which are able to harvest and manage light in both UV and Vis range, making ionization and Raman scattering more efficient. RaMassays were successfully applied to the detection of small (molecular weight, M.W. <400 Da) molecules with a key relevance in biochemistry and pharmaceutical analysis. Caffeine and cocaine were utilized as molecular probes to test the combined SERS/SALDI response of RaMassays, showing excellent sensitivity and reproducibility. The differentiation between amphetamine/ephedrine and theophylline/theobromine couples demonstrated the synergistic reciprocal reinforcement of SERS and SALDI. Finally, the conversion of L-tyrosine in L-DOPA was utilized to probe RaMassays as analytical tools for characterizing reaction intermediates without introducing any spurious effects. RaMassays exhibit important advantages over plasmonic nanoparticles in terms of reproducibility, absence of interference and potential integration in multiplexed devices.
SiO/TiO 核/壳（T-rex）珠被用作“一体化”建筑块材料，创建将等离子体自由表面增强拉曼散射（SERS）和表面辅助激光解吸/电离（SALDI）质谱（RaMassays）相结合的分析测定。这种多模态方法依赖于 T-rex 珠的独特光学性质，它能够在 UV 和 Vis 范围内收集和管理光，从而使离子化和拉曼散射更有效。RaMassays 成功地应用于检测具有生物化学和药物分析重要相关性的小分子（分子量，MW <400 Da）。咖啡因和可卡因被用作分子探针，以测试 RaMassays 的组合 SERS/SALDI 响应，显示出出色的灵敏度和重现性。安非他命/麻黄碱和茶碱/可可碱对的区分证明了 SERS 和 SALDI 的协同相互增强。最后，L-酪氨酸在 L-DOPA 中的转化被用于探测 RaMassays 作为分析工具，用于表征反应中间体，而不会引入任何虚假效应。RaMassays 在重现性、无干扰和潜在的多路复用设备集成方面比等离子体纳米粒子具有重要优势。
