Adapting aqueous biphasic systems to solid-phase extraction for bioanalytical applications: high-abundance protein depletion and prostate-specific antigen extraction from human serum.

Aqueous biphasic systems are investigated here, from standard liquid-phase to solid-phase extraction configurations for human serum pretreatment. Using prostate-specific antigen as a model biomarker, this strategy achieves >90% depletion of high-abundance proteins and demonstrates strong potential for bioanalytical applications compared to conventional precipitation methods.