Rapid and Selective Screening for Sulfhydryl Analytes in Plasma and Urine Using Surface-Enhanced Transmission Mode Desorption Electrospray Ionization Mass Spectrometry

摘要

Nylon mesh substrates were derivatized to includenVICATSH, a biotinylated reagent that contains both anphotolabile linking group and a thiol specific capturenagent. The enhanced mesh substrates were then usednto capture sulfhydryl analytes directly from urine andnplasma samples via covalent reaction between thenreactive thiols of the analytes and the iodoacetaminylnunit of VICATSH. Photocleavage of the labile linker wasnfollowed by direct analysis of the mesh surface viantransmission mode desorption electrospray ionizationn(TM-DESI). This chemoselective capture method pro-nmoted enrichment of sulfhydryl analytes and reducednmatrix interferences, thereby resulting in increasednanalytical performance of surface enhanced TM-DESI-nMS when compared to standard DESI-MS. The presentnwork describes the manufacture of the derivatizednmesh substrates and the quality control assessmentsnmade during the manufacturing process, the optimiza-ntion of the chemoselective capture method, and resultsnof experiments pertinent to biological applications.nIntegration of the chemoselective capture materialsnwith ambient ionization and tandem mass spectrometrynresults in a powerful combination of speed and selec-ntivity for targeted analyte screening.