A new microfluidics system with a hand-operated, on-chip actuator for immunosensor applications

This paper presents the realization of a portable, point-of-care and multi-target immunosensing lab-on-a-chip (LOC). The chip utilizes a novel on-chip actuating mechanism which uses a negative pressure to create thrust inside the channels to facilitate and control the fluid flow. No external instruments and/or sources were used to drive or control the liquid throughout the experimentation. LOC demonstrates a highly sensitive detection and quantification of a cancer marker, human-epidermal growth factor receptor (hEGFR) and a cardiac marker, interleukin 6 (IL-6) by impedimetric measurement approach. Without the use of any signal amplification methods (chemical), a dynamic detection limit of 3-8 ng/ml of hEGFR and 0.1-5 ng/ml of IL-6 in human serum was obtained. The extracted dissociation constants were calculated as 5.86 ng/ml (hEGFR) and 2.45 ng/ml (IL-6) by kinetic analysis. (C) 2012 Elsevier B.V. All rights reserved.