Direct observation of affinity reactions by reflected-mode operation of integrated optical grating coupler

Determination of the turnover number of the restriction endonuclease EcoRI using evanescent wave technology

“…In such devices, the primary signal may be correlated directly with the surface loading. The devices used in the present work detect the change of refractive index in the vicinity of the surface, as described elsewhere [2,3,4]. Thus, hybridization, binding, and release of enzyme and dissociation of parts of the product are observed.…”

“…The grating couplers were read out in the reflection mode as described elsewhere [4]. A scheme of the grating coupler and measurement system is given in Fig.…”

Size-selective analyte detection in an integrated optical Young interferometer biosensor

“…shows that  increases exponentially with, meaning that  can be determined less precisely. For a situation with three layers and assuming a phase precision of approximately 10 -4 fringes for the YI sensor [18], the detection limit (which is defined here as the minimum reliably detectable induced RI change which equals two times the precision) of n  is on average 5x10 -6 RIU, which is still comparable to other optical biosensors [25].…”

“…Both the incoupling and outcoupling configuration show an LOD of 10 -6 RIU. Furthermore, a setup configuration based on reflection-mode operation has been developed [18], which avoids moving parts in the setup. A lens is used to simultaneously irradiate a range of angles onto the grating.…”

“…YI sensors are based on the evanescent field sensitivity of guided modes propagating through the waveguide structure of the sensor [18]. Fig.…”