Experimental study of the evanescent‐wave photonic sensors response in presence of molecular beacon conformational changes

Abstract

An experimental study of the influence of the conformational change suffered by molecular beacon (MB) probes-upon the biorecognition of nucleic acid target oligonucleotides over evanescent wave photonic sensors-is reported. To this end, high sensitivity photonic sensors based on silicon photonic bandgap (PBG) structures were used, where the MB probes were immobilized via their 5' termination. Those MBs incorporate a biotin moiety close to their 3' termination in order to selectively bind a streptavidin molecule to them. The different photonic sensing responses obtained toward the target oligonucleotide detection, when the streptavidin molecule was bound to the MB probes or not, demonstrate the conformational change suffered by the MB upon hybridization, which promotes the displacement of the streptavidin molecule away from the surface of the photonic sensing structure.

Progress of infrared guided-wave nanophotonic sensors and devices

“…where Λ is the grating period, n eff is the effective index of Bragg grating. By monitoring the shift of the stop band edge, biochemical sensors based on Bragg gratings have been demonstrated [57][58][59]. If a phase shift region is introduced in the middle of the gratings, as illustrated in Fig.…”

“…More than twofold improvement in bulk and surface sensitivities was achieved compared to conventional MRR sensors. A degree of slow light effect also exists near the band edge of the periodic Bragg gratings and is naturally leveraged when monitoring the band edge shift in sensing [57][58][59].…”

New Method for Online Regeneration of Silicon-Based Nanophotonic Biosensors

“…This nanostructure was created by periodically introducing a modulation in the refractive index of a 1D photonic structure. It consisted of a single mode waveguide placed on top of a silicon oxide lower cladding with straight transversal elements [6,7], as shown in Figure 1b. The photonic detection was based on measuring the shift of the upper edge of the PBG.…”

“…FA is a denaturing agent for nucleic acids, which is commonly used in DNA solutions [5]. However, little is known about FA as a denaturing agent for miRNA bound to MB probes immobilized on silicon surfaces, which is what we are interested in [6]. Our study consisted of, after running a typical miRNA sensing experiment, flowing FA into water to dehybridize the probes and regenerate the sensor for performing further experiments.…”

Commercial Polycarbonate Track-Etched Membranes as Optical Chemical Sensors

“…For their design, different photonic structures have been developed. Most of them are based on the interaction of the evanescent optical field with the analyte [3]. However, the achievable sensitivity values of these sorts of structures are low, as only a low-intensity region of the optical field interacts with the analyte in a small surface.…”