| A resorcinol-formaldehyde (RF) polymer and matrix-embedded RF polymers were developed to be used as substrates for improved matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis and for selective analysis of biological samples.; Matrix molecules can be embedded within this polymer, which renders excellent spectra without the interference imposed by the matrix molecules for low molecular weight analytes. By embedding the matrix molecules in this polymer more uniform spectra are obtained, solving the prevalent problem associated with the traditional MALDI sample preparation methods.; The phenol groups on the polymer made it possible to attach aptamers selective to reactive green 19 and cocaine onto it directly, and gave high specific affinity toward the reactive green 19 and cocaine, respectively. The phenol groups on the polymer also made it possible to attach carboxylic acid groups which could then be reacted with amine-modified aptamers. This indirect aptamer-modified RF polymer has higher reaction efficiency than the direct aptamer-modified RF polymer, yield more aptamers at higher density on the polymer for affinity capture of analyte. This high specificity provided by the aptamers could make it a valuable tool to specifically retain the biomarkers of diseases and could be used for screen test for diseases. |
