Analytical Sciences

A Sol-gel Integrated Dual-readout Microarray Platform for Quantification and Identification of Prostate-specific Antigen

SangWook LEE,*1,*5 Jong Hyun LEE,*2 Hyuck Gi KWON,*2 Thomas LAURELL,*3 Ok Chan JEONG,*2,*4 and Soyoun KIM*5

*1 Department of Chemistry, University of Tokyo, Tokyo 113-0033, Japan
*2 Institute of Digital Anti-Aging Healthcare, Inje University, Gimhae 50834, Korea
*3 Department of Biomedical Engineering, Lund University, Lund SE-221 00, Sweden
*4 Department of Biomedical Engineering, Inje University, Gimhae 50834, Korea
*5 Department of Biomedical Engineering, Dongguk University, 10326, Korea

Here, we report a sol-gel integrated affinity microarray for on-chip matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) that enables capture and identification of prostate?specific antigen (PSA) in samples. An anti-PSA antibody (H117) was mixed with a sol?gel, and the mixture was spotted onto a porous silicon (pSi) surface without additional surface modifications. The antibody easily penetrates the sol-gel macropore fluidic network structure, making possible high affinities. To assess the capture affinity of the platform, we performed a direct assay using fluorescein isothiocyanate-labeled PSA. Pure PSA was subjected to on-chip MALDI-TOF-MS analysis, yielding three clear mass peptide peaks (m/z = 1272, 1407, and 1872). The sol-gel microarray platform enables dual readout of PSA both fluorometric and MALDI-TOF MS analysis in biological samples. Here we report a useful method for a means for discovery of biomarkers in complex body fluids.

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