The Design Of Novel Noble Metal Hybrids For Mass Spectrometry Analysis

As a soft-ionized analysis technology,matrix assisted laser desorption/ionization mass spectrometry?MALDI MS?is of great significance for the detection of bio-molecules such as protein,nucleic acid and metabolic molecules in clinics.In the MALDI MS,the analysis result largely depends on the selection of matrix.The use of traditional organic matrices was limited owing to strong interference signals in the low mass range and very poor reproducibility in the spot-to-spot.In recent years,many inorganic materials have been preferred matrices in MALDI MS compared with organic matrices.However,the application of these materials is very limited in real biological samples,such as for metabolites detection in bio-fluids and single nucleotide polymorphisms?SNP?detection in polymerase chain reaction?PCR?products.In this work,we developed a optimized silver nanoshells?SiO₂@Ag?as matrix in MALDI MS and achieved the analysis of small nutrients in human breast milk and the detection of adulteration in food.At the same time,we performed the quantitation of lactose in 20 breast milk samples by MALDI MS,compared to enzymatic method as current gold standard.Notably,the MALDI MS based on SiO₂@Ag can be advantageous due to easy sample preparation,low sample consumption and high speed of analysis and acquired a more accurate measurement.Besides,we designed a series of novel noble metal hybrid materials and studied the difference of MALDI performance between alloy materials and elemental noble metal materials.We applied the noble metal hybrids as matrix to the MALDI MS analysis of serum,cerebrospinal fluid and urine and achieved profiling and detection of small metabolites from complex samples.We also used the noble metal hybrids as co-matrix in analysis of nucleic acid and found that it could enhance the desorption/ionization efficiency of oligonucleotides by the synergistic effect with organic matrix.Our work not noly broadened the use of inorganic materials in MALDI MS,but also shed light on the application of noble metal hybrids in nutriology,metabonomics and clinic diagnoses.