Salim Hiba, Giménez Estela, Sanz-Nebot Victoria, Benavente Fernando
Department of Chemical Engineering and Analytical Chemistry, Institute for Research on Nutrition and Food Safety (INSA·UB), University of Barcelona, 08028, Barcelona, Spain.
Department of Chemical Engineering and Analytical Chemistry, Institute for Research on Nutrition and Food Safety (INSA·UB), University of Barcelona, 08028, Barcelona, Spain.
Anal Chim Acta. 2020 Dec 1;1139:169-177. doi: 10.1016/j.aca.2020.10.001. Epub 2020 Oct 6.
The use of ionic matrices (IMs) was evaluated as an alternative to conventional matrices to analyze microRNAs (miRNAs) by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). 2, 4, 6-Trihydroxyacetophenone (THAP), 6-aza-2-thiothymine (ATT) and 3-hydroxypicolinic acid (3-HPA) and their IMs with pyridine (PYR) and butylamine (BA) were studied to analyze a standard mixture of miRNAs: miR-21, let-7g and iso-miR-16. Among all the studied matrices, ATT-PYR at 75 mg/mL in acetonitrile (MeCN):HO (50:50, v/v) was selected as the optimal. Furthermore, addition of ammonium citrate dibasic (AC) as signal enhancer was mandatory to obtain an appropriate miRNA detection. ATT-PYR provided the best sensitivity, with limit of detection (LOD) up to 5 nM (equivalent to 1 fmol in the spot) and excellent spot-to-spot repeatability due to the improved homogeneity of the spots compared to the conventional matrices. The applicability of the established method to direct, multiplex and untargeted analysis of miRNAs in serum samples was also investigated.
评估了离子基质（IMs）作为传统基质的替代物，用于通过基质辅助激光解吸/电离质谱（MALDI-MS）分析微小RNA（miRNA）。研究了2,4,6-三羟基苯乙酮（THAP）、6-氮杂-2-硫代胸腺嘧啶（ATT）和3-羟基吡啶甲酸（3-HPA）及其与吡啶（PYR）和丁胺（BA）形成的IMs，以分析miRNA标准混合物：miR-21、let-7g和异-miR-16。在所有研究的基质中，选择乙腈（MeCN）:水（50:50，v/v）中浓度为75 mg/mL的ATT-PYR作为最佳基质。此外，必须添加柠檬酸氢二铵（AC）作为信号增强剂以实现适当的miRNA检测。ATT-PYR具有最佳灵敏度，检测限（LOD）高达5 nM（相当于斑点中1 fmol），并且由于与传统基质相比斑点的均匀性得到改善，具有出色的斑点间重复性。还研究了所建立方法在血清样品中miRNA直接、多重和非靶向分析中的适用性。
