Interfacing Biomolecules, Cells and Tissues with Nanowire-based Electrical Devices - Applications of Electrochemistry and Nanotechnology in Biology and Medicine - page 77

Figure 3. Continuation. (B) Schematic of MPC operation. (a) Primary antibodies to
multiple biomarkers, here PSA and carbohydrate antigen 15.3, are bound with a
photocleavable crosslinker to the MPC. The chip is placed in a plastic housing and
a valve (pink) directs fluid flow exiting the chip to either a waste receptacle or the
nanosensor chip. (b) Whole blood is injected into the chip with the valve set to the
waste compartment (black arrow shows the direction of fluid flow) and, if present
in the sample, biomarkers bind their cognate antibodies. (c) Washing steps follow
blood flow, and the chip volume (5 ml) is filled with sensing buffer before UV
irradiation (orange arrows). During UV exposure, the photolabile crosslinker
cleaves, releasing the antibody-antigen complexes into solution. (d) The valve is
set to the nanosensor reservoir (black arrow shows the direction of fluid flow) and
the 5 ml volume is transferred, enabling label free sensing to be performed to de-
termine the presence of specific biomarkers. (e, f) Scatter plots showing the concen-
tration of PSA (e) and CA15.3 (f) released from the MPC versus the concentration
of PSA and CA15.3 introduced in whole blood, respectively. Each data point repre-
sents the average of three separate MPC runs, and error bars represent one standard
deviation.