Improving immunosensor performances using an acoustic mixer on droplet microarray

A major drawback of protein microarrays is the lack of control of ligand immobilization at the surface of the chip which limits their performances and thus their impacts in in vitro diagnosis. To improve antibody (Ab) grafting during the spotting process on commercialized gold SPRi chips, we propose to produce a chaotic flow in every spotted droplet, by using an acoustic field, in order to disrupt the steady state of the reaction of Ab grafting. Our results show that acoustic mixing during Ab binding at the biochips surface increases their biorecognition performances of a mean factor of 2.7 in comparison with Ab layer grafted in a passive mode. Moreover, it increases statistically the homogeneity of the response over all the surface of the chips.