Eight-channel SiNx microring-resonator based photonic biosensor for label-free fluid analysis in the optical C-band *

Abstract

A lab-on-a-chip multichannel sensing platform for biomedical analysis based on optical silicon nitride (SiNx) microring-resonators (MRR) was established. The resonators were surface functionalized and finally combined with a microfluidic chamber for validation using an avidin-biotin ligand-binding assay. The results with a limit of detection (LOD) of 2.3•10 -5 and a mean intra-assay coefficient of variation (CV) of ±10.0 %, also under consideration of FDA guidelines, show promising future applicability for a wide variety of targets in the field of outpatient medical diagnostics and life science.

Repeatable Passive Fiber Optic Coupling of Single-Mode Waveguides in High-Precision Disposable Photonic Biosensors

“…Additionally, this relative measurement method allows for the qualitative detection of targeted binding events if the sensor is appropriately functionalized [17]. Further details regarding the used sensor concept can be found in [10]. The following sections will focus on the key coupling components, as well as their efficiency and usability testing.…”

“…The fabrication process was carried out on a 4-inch wafer using established PIC technology and includes a layer stack (top to bottom) of 420 nm plasma-enhanced chemical vapor deposition (PECVD) SiO2, 200 nm low-pressure chemical vapor deposition (LPCVD) Si3N4, 3.4 µm thermal SiO2, and a 525 µm silicon (Si) substrate. The process employs stepper lithography with dry etching and chemical vapor deposition (CVD), as described in [10,20]. The MRR waveguides are stripped of the cladding through a lift-off process to create an active sensor area.…”

“…The resulting data are presented in Figure 9. For further details on the sensor MRR itself, including parameters like sensitivity and the limit of detection, please refer to [10].…”

“…However, the scope of the investigation here is centered on the coupling system itself, which is designed to be adaptable to a wider range of applications. A comprehensive description of the sensor element is available in [10]. Additionally, the sensors are contextualized within the framework of other related studies therein.…”