Detecting proteins via surface assisted laser desorption/ionization mass spectrometry (SALDI-MS) method is still highly challenging, and only few examples of nanomaterials have been demonstrated to perform such detection so far. In this study, carbon nanowalls (CNWs), vertically aligned graphene sheet-based materials, presenting specific morphology, dimensions, and boron doping levels have shown improved performances for both qualitative and quantitative detection of Cytochrome C under optimized experimental conditions. Boron doped carbon nanowalls (B-CNWs) with a [B]/[C] ratio of 5000 ppm and growing time of 4 h have shown the best performance in terms of signal intensity and reliability. Then, the detection of ricin, a ribosomal-inhibiting protein (RIP) classified as category B bioterrorism agent by CDC (Centre of Disease and Control and Prevention), was performed. For the first time, direct SALDI-MS detection of ricin B chain was reported without tedious sample preparation steps or database interrogation, and results were obtained within few minutes and a limit of detection (LOD) of 0.5 pmol/μl was obtained. Thanks to the introduction of galactosamine residues on B–CNW, we were able to selectively detect ricin B chain protein in complex media such as serum and soft drinks with enhanced signal intensity. B-CNWs are not toxic and are adaptable to any commercial MALDI-TOF mass spectrometer, showing their great potential as SALDI based materials.

通过检测蛋白质表面辅助激光解吸/电离质谱 (SALDI-MS) 方法仍然极具挑战性，到目前为止，只有少数纳米材料被证明可以进行这种检测。在这项研究中，碳纳米壁 (CNW)、垂直排列的石墨烯片基材料具有特定的形态、尺寸和硼掺杂水平，在优化的实验条件下显示出对细胞色素 C 的定性和定量检测的改进性能。[B]/[C] 比为 5000 ppm 且生长时间为 4 小时的硼掺杂碳纳米墙 (B-CNW) 在信号强度和可靠性方面表现出最佳性能。然后，对被 CDC（美国疾病控制与预防中心）归类为 B 类生物恐怖分子的核糖体抑制蛋白 (RIP) 蓖麻毒素进行了检测。首次报告了直接 SALDI-MS 检测蓖麻毒素 B 链，无需繁琐的样品制备步骤或数据库查询，并在几分钟内获得结果，检测限 (LOD) 为 0.5 pmol/μl。由于在 B-CNW 上引入了半乳糖胺残基，我们能够选择性地检测血清和软饮料等复杂介质中的蓖麻毒素 B 链蛋白，并具有增强的信号强度。B-CNW 无毒，适用于任何商用 MALDI-TOF 质谱仪，显示出它们作为 SALDI 基材料的巨大潜力。由于在 B-CNW 上引入了半乳糖胺残基，我们能够选择性地检测血清和软饮料等复杂介质中的蓖麻毒素 B 链蛋白，并具有增强的信号强度。B-CNW 无毒，适用于任何商用 MALDI-TOF 质谱仪，显示出它们作为 SALDI 基材料的巨大潜力。由于在 B-CNW 上引入了半乳糖胺残基，我们能够选择性地检测血清和软饮料等复杂介质中的蓖麻毒素 B 链蛋白，并具有增强的信号强度。B-CNW 无毒，适用于任何商用 MALDI-TOF 质谱仪，显示出它们作为 SALDI 基材料的巨大潜力。