Development of Autonomous Loaded-catalysts Phase-transfer Assay for Diagnosis

Abstract

An initial stimulus in cells is amplified with huge signals through biochemical cascade reactions involving activations of proenzymes. Mimicking this cells’ approach as an ultrasensitive biosensing strategy, however, is challenging due to the functional complexity of proenzymes, which can recognize a biomarker and amplify the signal simultaneously. Herein, we report a pronanozyme assay for diagnosis by integrating a biphasic reaction system for spatial separation of recognition and amplification process, and catalysts-loaded nanocarriers as a pronanozyme for signal transduction. A specific cleavage reaction by the target biomarker can activate the pronanozyme, phase-transferring the loaded catalysts through the interfacial migration of the nanocarriers. The transferred catalysts can generate the signal molecules, indicating the presence of target biomarkers. The practical use of this amplification approach in biosensing was demonstrated through the detection of Caspase 3 and Cathepsin B as a biomarker of apoptosis and cancer at femtomolar concentration levels, respectively. Furthermore, this pronanozyme assay can be applied to a well-plate system for high-throughput sensing and can be performed in an ultrafast one-step process.