One of the main features of blood cells are their non-adherent properties that enable them to flow in the blood stream with minimum interaction on the vessel walls. Thus, blood cell analysis on biochips is more challenging than with naturally adherent-cells! Moreover, individual cell analysis is also a major concern as the variability of individual responses also gives better insights into cellular responses.
B lymphocytes (Ø ≈12 μm) immobilized on a matrix of 8 x 8 blocks.
The glass substrate has a gold coverage.
We recently developed a biochip, electrochemically arrayed, capable of individual blood cell capture on each feature, thanks to a three-step process. The LAAS laboratory builds silicon-made micro-cantilevers, similar to a series of ink pencils. These micro-pencils are filled with a solution containing both monomers and antibodies. Once in contact with the biochip (covered by a nanometric-thick gold layer), the polymer entrapping the antibodies is electro-generated. Eventually, suspensions of blood cells are added to the biochip and cells presenting specific antigens on their outer membrane are selectively captured for specific antibody features. We have taken one step closer toward individual blood cell analysis.
Silicon microcantilevers with a gold coverage.