Self-assembly of super-hydrophobic PMMA microspheres on silicon wafer as MALDI-MS chip for rapid quantification of peptides

• Published in: Sensors and actuators. B, Chemical Vol. 306; p. 127573
• Main Authors: Dou, Shuzhen, Li, Ning, Wang, Xueyun, Zhu, Qunyan, Wang, Zhongshun, Lu, Nan
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.03.2020; Elsevier Science Ltd
• Subjects: Crystallization; Hydrophobicity; Ions; MALDI-MS; Mass spectrometry; Microspheres; Milk; Peptides; PMMA chip; Polymethyl methacrylate; Quantification; Reproducibility; Self-assembly; Sensitivity; Silicon wafers; MALDI-MS; PMMA chip; Self-assembly; Peptides; Quantification
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2019.127573

•A novel super-hydrophobic structured-PMMA chip for MALDI-MS is prepared by a simple self-assembly method.•The MALDI-MS detection reproducibility and sensitivity are highly improved with this chip compared to the conventional steel target.•Different peptides can be quantified in a broad range with this chip by MALDI-MS without internal standard.•Different practical peptides samples can be quantified in a broad range with this chip without internal standard by MALDI-MS. Rapid quantification of peptides by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a challenge. Herein, we prepared a super-hydrophobic poly(methyl methacrylate) (PMMA) structured chip for quantifying peptides without internal standard by improving the detection reproducibility and sensitivity. The chip was formed by PMMA microspheres through a self-assembly method. As a good adsorbent of peptides, PMMA microspheres make peptides distributed uniformly on the chip, resulting in the elimination of the coffee ring effect and the homogeneous co-crystallization of peptides/matrix. The relative standard deviations (∼ 10 %) and coefficients of determination (∼ 0.99) are satisfactory when detecting 3 standard peptides, which show that the chip is applicable for rapid quantification of peptides. The limit of detection is improved by 1000-fold on this chip compared with conventional steel target because of the enrichment of the super-hydrophobicity. It can be concluded that the detection reproducibility and sensitivity are significantly improved by the super-hydrophobic structured-PMMA chip. The applicability of the chip for practical samples is demonstrated by quantifying bacitracin A in milk extract and bradykinin1-7 in serum with good linearities. The structured-PMMA chips exhibit competitive advantages for quantitative analysis of peptides, which have a great potential for proteomic research.