Multi-analytic grating coupler biosensor for differential binding analysis

In this paper, a multiple-channel extension of a dual-grating coupler biosensor is presented as a solution for the problem of resolving different selectivities, usual when heterogeneous samples are analyzed. Several differently functionalized channels can perform quantitative analysis of competiting recognition events, suppress shifts due to buffer changes and even monitorize drifts coming from the light source. Here, the multiple-channel approach is developed and proven for a four-channel configuration, providing a resolution limit of 10−5 Refractive Index Units (RIU) and with an a potentially unlimited scalability. Finally, a differential HSA recognition event is monitored, at both an IgG functionalized channel and at a blocked one.