Directional fluorescence emission co-enhanced by localized and propagating surface plasmons for biosensing

Abstract

We investigated the simultaneous excitation of localized surface plasmons (LSPs) and propagating surface plasmons (PSPs) on a thin metallic film with an array of nanoholes for the enhancement of fluorescence intensity in heterogeneous bioassays. Experiments supported by simulations reveal that the co-excitation of PSP and LSP modes on the nanohole array in a Kretschmann configuration allows for fluorescence enhancement of about 10(2) as compared to a flat Au surface irradiated off-resonance. Moreover, this fluorescence signal was about 3-fold higher on the substrate supporting both PSPs and LSPs than that on a flat surface where only PSPs were resonantly excited. Simulations also indicated the highly directional fluorescence emission as well as the high fluorescence collection efficiency on the nanohole array substrate. Our contribution attempts to de-convolute the origin of this enhancement and identify further ways to maximize the efficiency of surface plasmon-enhanced fluorescence spectroscopy for implementation in ultra-sensitive bioassays.

Negative permittivity adjusted by SiO2-coated metallic particles in percolative composites

“…Accordingly, these materials are also called intrinsic metamaterials or a M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 3 new concept "metacomposites". [5][6][7][8] In recent years, intrinsic metamaterials with tunable negative permittivity begin to gain extensive research attention due to the potential application, such as plasmons biosensing [9], microwave funneling [10], and electromagnetic shield [11], sensors [12][13][14], negative permittivity materials can also be used in left-handed materials when combined with negative permeability materials, etc. [15][16][17] However, the recent investigations of negative permittivity mainly focus on how to explain and realize negative permittivity.…”

Surface plasmon-enhanced fluorescence on Au nanohole array for prostate-specific antigen detection

“…The future work includes the improvement of nanostructure for high enhancement of fluorescence intensity and possibility for highly directional fluorescence emission. 52 We believe that the method of simultaneously exciting LSP and PSP modes for fluorescence enhancement would pave the way to significantly improve the sensitivity of molecule detection and offers as a potential candidate for the early cancer diagnosis and food safety monitoring.…”

Surface plasmon sensing with broadband coherent laser pulses

“…For a pulse of a mixed polarization state the distribution of the spectral intensity over angle and wavelength can be calculated from Eqs. (7)(8)(9), and the result is shown in Fig. 5(a).…”

“…Multi-wavelength detection can be used for broadband absorption measurements of films using the reflected intensity as well as by detecting the phase response [22]. SP resonances with incoherent radiation were used for fluorescent ultra-sensitive detection in bioassays [23] and for hyperspectral-imaging of binding biomolecules in a miniaturized sensor [24].…”