High sensitivity optical biosensor based on polymer materials and using the Vernier effect

Abstract

We demonstrate the fabrication of a Vernier effect SU8/PMATRIFE polymer optical biosensor with high homogeneous sensitivity using a standard photolithography process. The sensor is based on one micro-resonator embedded on each arm of a Mach-Zehnder interferometer. Measurements are based on the refractive index variation of the optical waveguide superstrate with different concentrations of glucose solutions. The sensitivity of the sensor has been measured as 17558 nm/RIU and the limit of detection has been estimated to 1.1.10 RIU.

Optical Refractive Index Sensors with Plasmonic and Photonic Structures: Promising and Inconvenient Truth

“…The present world record for bulk RI sensitivity is around a few 10,000 nm/RIU, which was achieved by a waveguide surface plasmon resonance (SPR) sensor [75], a nano Lycurgus cup array (NCLA) sensor [46], fibre grating sensors [54,76,77], interferometer sensors [23,[78][79][80][81][82][83][84][85][86][87][88][89][90][91], whispering gallery mode (WGM) sensors [92][93][94][95]. Meanwhile, high values of FoM on the order of 1,000 RIU −1 appear for various RI sensors (mostly dielectricbased), e.g., a nanohole sensor [982], the NCLA sensor [46], tilted fibre Bragg grating (TFBG) sensors [52,299], interferometer sensors [84,87,88,90,91,399,404,417], photonic crystal cavity (PCC) sensors [58,62,504,505,520,524,530,536,[983]…”

“…Toward the similar research direction, cascaded MZI and RR have been proposed for RI sensing [94,95,[594][595][596][597][598]. The bulk RI sensitivity of 21,500 nm/RIU was obtained for the cascaded MZI-RR sensor shown in Figure 12, panel B, f, which was ∼ 22× as high as that of MZI sensor [94].…”

“…However, the active sensing region of this cascaded MZI-RR sensor is MZI only, whereas the RR acts as the reference. On the other hand, Azuelos et al proposed another cascaded MZI-RR sensor [95], as shown in Figure 12, panel B, g. In this cascaded MZI-RR sensor, the RR embedded on the upper arm of the MZI acts as the reference RR, whereas the RR embedded on the lower arm and exposed to the sensing medium (represented by the white rectangle) function as the active sensing part. The RI sensitivity of 17,558 nm/RIU with the FoM of 3,849.9 RIU −1 was achieved with such MZI-RR sensor.…”

“…(WGM) resonator sensors [92][93][94][95]. On the other hand, the highest FoM is reaching 100,000 RIU −1 , which appears for various dielectric-based RI sensors such as PCC sensors [96,97] and WGM resonator sensors [98][99][100].…”

Study of a Broadband Difference Interferometer Based on Low-Cost Polymer Slab Waveguides

“…Many interferometric structures are designed and implemented using various types of polymers. SU-8 is a common polymer used in this application [32,33].…”