A Mass-Producible and Versatile Sensing System: Localized Surface Plasmon Resonance Excited by Individual Waveguide Modes

Abstract

A plasmonic sensing system that allows the excitation of localized surface plasmon resonance (LSPR) by individual waveguide modes is presented conceptually and experimentally. Any change in the local environment of the gold nanoparticles (AuNPs) alters the degree of coupling between LSPR and a polymer slab waveguide, which then modulates the transmission-output signal. In comparison to conventional LSPR sensors, this system is less susceptible to optical noise and positional variation of signals. Moreover, it enables more freedom in the exploitation of plasmonic hot spots with both transverse electric (TE) and transverse magnetic (TM) modes. Through real-time measurement, it is demonstrated that the current sensing system is more sensitive than comparable optical fiber plasmonic sensors. The highest normalized bulk sensitivity (7.744 RIU) is found in the TM mode. Biosensing with the biotin-streptavidin system shows that the detection limit is on the order of 10 M of streptavidin. With further optimization, this sensing system can easily be mass-produced and incorporated into high throughput screening devices, detecting a variety of chemical and biological analytes via immobilization of the appropriate recognition sites.

Spin-Orbital Conversion of a Strongly Focused Light Wave with High-Order Cylindrical–Circular Polarization

“…The coincidence between the experimentally generated beam and those studied theoretically was verified using the Jones formalism. The results obtained in terms of controlling the intensity maxima allow for the transverse mode analysis of laser beams in waveguide-based sensors [ 38 , 39 ]. This kind of CVB can be used in phase-sensitive surface plasmon resonance biosensors with high resolution [ 40 ], or in graphene biosensors for real-time subcellular imaging [ 41 ].…”

Au-nanoparticles strip-loaded channel waveguide

“…AuNPs were deposited as previously described with modifications. 3 A thin line (< 0.5 mm) was carved out of a piece of silicon sheet (Grace Bio-Labs, 0.5 mm thick) that is the same size as the slab waveguide (2.5 cm x 5 cm, fused silica substrate with coupling grating and polystyrene waveguide spin coated on top) with two scalpel blades (X-Acto, no. 2) pressed together.…”

“…Plasmonic-waveguide hybrid sensors [2][3][4] are a type of LSPR sensors known for their robust and compact structures, flexible polarizations, and high signal to noise ratios. We have recently demonstrated a high-sensitivity sensor in a simple slab waveguide transmission experiment with excellent signal and signal-to-noise-ratio 3 , despite the waveguide mode, with a wavelength very close to the LSPR, traveling through a 1.6-cm circular spot of AuNPs with a density of 2.7×10 3 particles/μm 2 . Multiplexing, with n analytes in parallel, is not economic with such spot arrangement, due to the large size requirement and inefficient use of gold.…”

Infrared Metasurface Augmented by Deep Learning for Monitoring Dynamics between All Major Classes of Biomolecules

“…The complexity of the tackled bioanalytical studies go hand in hand with the wealth of available DNN training data, which is both a blessing and a curse, as extensive data collection can be tedious but also brings the prospect of eventually unraveling the biomolecular events. [48] Looking forward to future developments, one can envision the adaption of the technology to become compatible with mass-production methods [19,[49][50][51][52] and miniaturization efforts [53][54][55][56] for convenient diagnostics and therapeutics. This will probably require a move away from Au as the resonator material, and a Fourier-transform infrared (FTIR) spectroscope as the measurement instrument, because the former is not complementary metal-oxide-semiconductor (CMOS)-compatible and the latter is bulky and expensive.…”