BUFFER-FREE CONTINUOUS-FLOW BIOSENSORS FOR REAL-TIME MONITORING OF SMALL BIOMOLECULES IN HUMAN BIOFLUIDS BY ION CONCENTRATION POLARIZATION

This paper presents a novel integrated biosensor capable of continuous real-time dynamic monitoring of small biomolecules (i.e., adenosine triphosphate – ATP/cancer drug doxorubicin – DOX) in human biological samples (i.e., artificial saliva/human serum) by integrating the electrochemical aptamer-based sensors (i.e., e-aptasensors with electrical signals) into an electrokinetics-based nanofluidic device. A proof-of-concept device based on a detection method using aptamers’ optical signals (i.e., fluorescence intensity) has been successfully demonstrated previously in [1-2]. Herein, the advantage of the current biosensors lies in its fast response time (i.e., sub-minute temporal resolution) due to the use of electrical signals, high sensitivity (i.e., bind to different targets ATP/DOX) due to an optimization of e-aptasensors, and a minimal intervention. A core technology of this biosensor is buffer-free and online signal regeneration in patient samples without the use of bulky clean buffer solutions by utilizing ion concentration polarization (ICP) phenomenon in the nanofluidic device. More importantly, with simple operations and all-electronic architecture, the proposed biosensor opens the possibility in transferring into a portable device for personalized health monitoring or applications in remote wireless healthcare and timely therapeutics.