Purpose

The number of studies utilizing the matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has significantly increased over the past years. This technique features excellent sensitivity and speed of analysis for ionic compounds such as proteins, peptides, nucleic acids and small metabolites. Detection of small metabolites by MALDI-MS is essential for early diagnosis and monitoring of various diseases and understanding their pathogenesis.

Method

For metabolic analysis, conventional matrix and designed materials have certain limitations in terms of undesired aggregations, synthetic chemicals, low reproducibility and high cost. Herein, we report a novel application for enhanced MALDI-MS detection of small metabolites (MW < 500 Da) using biosynthesized silver nanoparticles (Ag-NPs) from the leaf parts of Cudrania tricuspidata as a green metal matrix.

Result

We were able to detect standard molecules (glucose, lysine, sucrose and glutamic acid) at a low detection limit (4–20 nmol) and achieve MALDI-MS profiling of these molecules at different dosages utilizing green metal matrix. The subsequent peaks were of higher intensity and with low background noise in comparison with those obtained using conventional α-cyano-4-hydroxycinnamic acid (CHCA) matrix and other nanomaterials. The tolerance assessment further demonstrated the analytical sensitivity of the green metal matrix in complex protein/salt mixture. In addition, we were able to detect 13 low molecular weight metabolites in 10× delude human healthy serum samples and another distinct 18 low molecular weight compounds in pancreatic cancer serum samples. Furthermore, the commonly used matrix, CHCA and other nanomaterial matrices, including silver, gold, SiO₂@Ag and TiO₂ nanoparticles, were also used in this study to compare with green noble metals (Ag) for the detection of small metabolites.

Conclusion

Our work highlights the enhancement of green substrates as a matrix in the real-case analysis of small metabolites, besides the successful detection of the standard molecules using MALDI-MS. The green metal matrix offers future prospects in systems biology and disease detection and will have an industrial application for being economic, eco-friendly and rapid over the large scale chemical synthesis matrix.

中文翻译：

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使用基质辅助激光解吸电离质谱法（MALDI-MS）的新型绿色银纳米颗粒作为小分子检测的基质

目的

在过去几年中，利用基质辅助激光解吸/电离质谱（MALDI-MS）进行的研究数量已大大增加。该技术具有出色的灵敏度和分析速度，适用于离子化合物，例如蛋白质，肽，核酸和小代谢物。MALDI-MS检测小代谢物对于各种疾病的早期诊断和监测以及了解其发病机理至关重要。

方法

对于代谢分析，常规基质和设计的材料在不希望的聚集，合成化学物质，低重现性和高成本方面具有一定的局限性。在这里，我们报告了一种新的应用，该技术使用了来自Cu鱼叶片的生物合成的银纳米颗粒（Ag-NPs）作为绿色金属基质，用于增强小代谢物（MW <500 Da）的MALDI-MS检测。

结果

我们能够以低检测限（4–20 nmol）检测标准分子（葡萄糖，赖氨酸，蔗糖和谷氨酸），并利用绿色金属基质以不同剂量对这些分子进行MALDI-MS分析。与使用常规α-氰基-4-羟基肉桂酸（CHCA）基质和其他纳米材料获得的峰相比，随后的峰具有更高的强度和较低的背景噪声。耐受性评估进一步证明了绿色金属基质在复杂蛋白质/盐混合物中的分析灵敏度。此外，我们能够在10倍虚假的人类健康血清样品中检测到13种低分子量代谢物，在胰腺癌血清样品中检测出另外18种低分子量化合物。此外，常用的基质，CHCA和其他纳米材料基质（包括银）本研究中还使用了₂ @Ag和TiO ₂纳米颗粒，与绿色贵金属（Ag）进行了比较，以检测小的代谢物。

结论

我们的工作着重强调了绿色底物在小代谢物的实际分析中作为基质的增强作用，此外还使用MALDI-MS成功检测了标准分子。绿色金属基质为系统生物学和疾病检测提供了未来的前景，并且在经济，生态友好和快速的大规模化学合成基质方面将具有工业应用。