Enhanced Surface Plasmon Resonance Research Articles

D-Shaped Surface Plasmon Photonic Crystal Fiber Temperature Sensor

A D-shaped photonic crystal fiber (PCF) temperature sensor based on surface plasmon resonance (SPR) with high sensitivity and high figure of merit is presented in this paper. To enhance surface plasmon resonance, the gold film is deposited on the polished flat of D-shaped photonic crystal fiber. Ethanol and chloroform are employed as temperature-sensitive materials, which are placed on the outside of the fiber to detect temperature changes. When the phase-matching condition is met, the core mode couples with the surface plasma mode. The finite element method is used to perform all numerical simulations of sensor characteristics in the COMSOL software. The results show that the highest sensitivity of the sensor can reach 6.36 nm/°C and the maximum figure of merit (FOM) is 0.3440/°C in the range of −5 ~ 60 °C. To our knowledge, the achieved sensing characteristics are significantly better than those of the current PCF temperature sensors. Furthermore, excellent linearity with a polynomial fit R2 as high as 0.9981. The proposed sensor has exceptional performance in terms of temperature detection range, sensitivity, FOM, and fabrication, making it suitable for a wide variety of biochemical and medical applications.

Design of Au nanorods-based plasmonic catalyst in combination with nanohybrid Pd-rGO layer for boosting CO2 hydrogenation to formic acid under visible light irradiation

In recent years, research on the use of surface plasmon resonance phenomena induced by visible to near-infrared light for photocatalytic reactions has attracted much attention from the viewpoint of solar energy utilization. It has been extensively researched that the plasmon-mediated catalytic reaction can be promoted due to the injection of energetic hot electrons originating during the relaxation process of the surface plasmon resonance (SPR) into the reaction substrate molecules. In this report, we have prepared Pd/Au NRs@rGO nanocatalyst in which Au nanorods (NRs) with plasmonic properties are surrounded by a layer of reduced graphene oxide (rGO) with excellent electrical conductivity, and Pd nanoparticles (NPs) are supported on the Au NRs to efficiently transport hot electrons to the reaction substrate. The successful synthesis of the catalyst was characterized by HAADF-STEM, TEM, UV–vis, XRD, XAFS, and ICP analysis. The applicability of the prepared catalyst was tested in the photocatalytic reduction of CO2 to formic acid (FA) reaction under visible light irradiation. A photocatalytic FA yield of 1.7 μmol was obtained in 24 h, which was 2.7-fold higher than in dark reaction conditions. The SPR enhancement of Pd/Au NRs in combination with rGO in Pd/Au NRs@rGO catalyst led to the superior product yield of FA under visible light irradiation and room temperature conditions.

Sensitivity enhancement of SPR based refractive index sensor in VIS-NIR region by using ZnS and PVP

A highly sensitive optical sensor is presented. This sensor is having multilayer structure that is designed and optimized theoretically by using Zinc Sulfide (ZnS) and Polyvinylpyrrolidone (PVP). The optical sensor proposed here is based on Surface Plasmon Resonance (SPR) technique by using Kretschmann configuration. This SPR sensor is designed with BK-7 prism which is coated with silver (Ag), overlayers ZnS and PVP in sequence. Silver is the plasmonic metal, PVP and ZnS are polymer and dielectric respectively and they perform the interaction with analyte and sensitivity enhancement however ZnS contributes more to enhance the sensitivity. For the characterization of multilayer Ag/ZnS/PVP structure of optical sensor, spectral interrogation mode is used. The surface plasmon resonance wavelength was calculated for each concentration. It shifts linearly towards higher wavelength with the increasing concentration of the analytes from 1.33 to 1.35 refractive index when interact with sensing surface. The sensitivity of the sensor is found to be 8537.06 nm/RIU throughout. The spectral range of proposed sensor is Visible-Near Infra Red (VIS-NIR) region from 600 to 1050 nm. The detection accuracy (DA) decreases with increasing concentration of analytes. Figure of merit (FOM) is also having same nature as DA. The sensitivity of the proposed sensor is quite high in comparison to other sensors. The proposed sensor will be useful to sense the chemical and biological compounds within its detection range (from 1.33 to 1.35 refractive index) in VIS-NIR region from experimental point of view.

Plasmon-enhanced hydrogen evolution on Pt-anchored titanium nitride nanowire arrays

Plasmonic materials integrated with electrochemical catalysts produce hot carriers that improve the catalytic activity of the hydrogen evolution reaction (HER). Previous studies have mainly focused on noble metal-based plasmonic materials. Herein, an efficient catalyst comprising non-noble TiN as the plasmonic booster and Pt nanoparticles (NPs) as the cocatalyst is prepared on carbon cloth (CC) (Pt/TiN/CC) by nitridation of TiO2 in NH3 and electrodeposition. The HER properties are improved significantly as manifested by a small overpotential of 16 mV at a current density of 10 mA cm−2 (η10) as well as 2-fold decay in η10 compared to the control experiment conducted in darkness (33 mV). To investigate the role of light-excited hot electrons in the reduction of protons to H2, Pt/TiOx/CC is irradiated with UV–visible light in the control experiment and the superior characteristics of Pt/TiN/CC corroborate the surface plasmon resonance (SPR) enhancement rendered from the TiN nanowire arrays. This study provides a fundamental understanding of hot electronics generated by SPR and insights into the design of non-noble electrocatalysts for HER and other applications.

Visible light assisted trace gaseous NO2 sensor with anti-humidity ability via LSPR enhancement effect

Transition metal dichalcogenides (TMDs) have been received widespread attention for NO2 detection at room temperature. However, the TMDs-based gas sensors usually possess inferior response capability and suffer from humidity interference due to lack of sufficient reaction activation energy, which seems tough to achieve the detection of ppb-level gases and hinder the practical applications. Herein, we propose a visible light-assisted-type gas sensor based on Au-decorated WS2, endowing high-performance detection of NO2 at room temperature. Benefited from the localized surface plasmon resonance (LSPR) enhancement effect induced by the modified Au nanoparticles (NPs), the visible light-assisted Au/WS2 gas sensor can implement the detection of NO2 gas as low as 20 ppb. Moreover, the maximum drift of the sensor response value is only 3% in the range of 10%−90% RH, indicating the stabilized anti-humidity ability. The effective regulation of transmission channel by the modified noble metal and the enhancement of visible light absorption of WS2 through taking full advantage of the LSPR effect are the main reasons for realizing low concentration detection and improving the anti-humidity ability. Therefore, the visible light-assisted gas detection mode can serve as a proof-of-concept to provide an effective approach for the detection of trace gases at room temperature.

Broadband Absorption Antenna Based on High Refractive Index Tungsten Metal-Insulator-Meta Metamaterial Nano Ring Array

Antennas for solar energy collection, for the problem of complex antenna structure and narrow absorption band, a metal-insulator-metal (MIM) nano ring array antenna based on metamaterial is proposed, which has high-efficiency light absorption characteristics in the broadband range of visible light and near-infrared light. Based on surface plasma theory, the proposed antenna is only composed of two W layers of metal and one Al2O3 layer of insulator medium, and has an a verage absorption rate of 96.93% in the range of 400–1600 nm. In addition, it is found that this kind of super light-absorbing capability is independent of the incoming light polarization state and can maintain an average of 91% for an incident angle as large as±60°. Furthermore, the perfect absorption performance of MIM nano ring array antenna based on metamaterial can be explained by the synergistic effect of localized surface plasmon resonance enhancement and Fabry-Perot resonance.

Magnetic and Optical Properties of Au-Co Solid Solution and Phase-Separated Thin Films and Nanoparticles.

The chemical composition and morphology of AuxCo1-x thin films and nanoparticles are controlled via a combination of cosputtering, pulsed laser-induced dewetting (PLiD), and annealing, leading to tunable magnetic and optical properties. Regardless of chemical composition, the as-deposited thin films and as-PLiD nanoparticles are found to possess a face-centered cubic (FCC) AuxCo1-x solid-solution crystal structure. Annealing results in large phase-separated grains of Au and Co in both the thin films and nanostructures for all chemical compositions. The magnetic and optical properties are characterized via vibrating sample magnetometry (VSM), ellipsometry, optical transmission spectroscopy, and electron energy loss spectroscopy (EELS). Despite the exceptionally high magnetic anisotropy inherent to Co, the presence of sufficient Au (72 atom %) in the AuxCo1-x solid solution results in superparamagnetic thin films. Among the as-PLiD nanoparticle samples, an increased Co composition leads to a departure from traditional ferromagnetism in favor of wasp-waisted hysteresis caused by magnetic vortices. Phase separation resulting from annealing leads to ferromagnetism for all compositions in both the thin films and nanoparticles. The optical properties of AuxCo1-x nanostructures are also largely influenced by the chemical morphology, where the AuxCo1-x intermixed solid solution has significantly damped plasmonic performance relative to pure Au and comparable to pure Co. Phase separation greatly enhances the quality factor, optical absorption, and electron energy loss spectroscopy (EELS) signatures. The enhancement of the localized surface plasmon resonances (LSPRs) scales with the reduction in Co composition, despite EELS evidence that excitation of the Co portions of a nanoparticle can provide a similar, and in some instances enhanced, LSPR resonance compared to Au. This behavior, however, is seemingly limited to the LSPR dipole mode, while higher-order modes are greatly damped by a Co aloof position. This observed magneto-plasmonic functionality and tunability could be applicable in biomedicine, namely, cancer therapeutics.

Sensitivity enhancement of fiber surface plasmon resonance (SPR) sensor based upon a gold film-hexagonal boron nitride—molybdenum disulfide structure

A new gold film-molybdenum disulfide (MoS2)-hexagonal boron nitride (h-BN) three-layer sensing structure is reported for sensing applications. The strong photoelectric conversion of MoS2 and the wide forbidden band of h-BN are used to enhance the surface plasmon resonance of the gold film which greatly enhance the sensitivity of the sensor. The Au film was deposited on the optical fiber by controlled vacuum sputtering to monitor the thickness. The MoS2 nanolayer was deposited on the surface of the gold film by electrostatic adsorption and the hexagonal boron nitride nanolayer was subsequently superimposed to complete the preparation. The sensitivity of the prepared sensor was increased to 3803.0 nm/RIU, which is 71.5% higher than for the common gold film sensor. These results confirmed that this approach significantly upgraded the sensor performance. The newly proposed SPR sensor performed well using a simple structure, is low-cost, offers high accuracy and favorable specificity, and may be used for small molecule detection for medical applications.

Electrochemical Growth of Ag/Zn Alloys from Zinc Process Solutions and Their Dealloying Behavior

This study investigates the sustainable preparation of Ag/Zn alloys from a simulated zinc process solution (20 ppm Ag, 65 g/L Zn, and 10 g/L H2SO4) via electrodeposition-redox replacement (EDRR) and the electrochemical dealloying behavior of the Ag/Zn alloys. Results indicate that Ag/Zn deposits with diverse compositions and microstructures can be obtained at room temperature without any complexing agents, simply by varying EDRR parameters like deposition time, deposition potential, and redox replacement time. Two types of Ag/Zn intermetallics (Zn0.96Ag0.04 and Ag0.76Zn0.24) were identified by the combination of X-ray diffraction (XRD) and anodic linear sweep voltammetry. Mass-transfer limitations have significant effects on the growth process, and a nucleation-growth mechanism from Ag/Zn particles into dendrites with increased EDRR cycles is introduced: with EDRR parameters favoring mass-transfer limitations (higher overpotentials, longer deposition times, and shorter redox replacement times), a more dendritic morphology of Ag/Zn alloys is achieved. The selective dissolution of Zn (i.e. dealloying) allowed the formation of silver-rich surfaces with an enhanced surface plasmon resonance behavior, which can be readily tuned by EDRR and dealloying parameters. These results highlight the significant potential of the EDRR-dealloying route to produce different types of Ag/Zn alloys and optically functional materials directly from base metal process solutions.

Measurement precision enhancement of surface plasmon resonance based angular scanning detection using deep learning

Angular scanning-based surface plasmon resonance measurement has been utilized in label-free sensing applications. However, the measurement accuracy and precision of the surface plasmon resonance measurements rely on an accurate measurement of the plasmonic angle. Several methods have been proposed and reported in the literature to measure the plasmonic angle, including polynomial curve fitting, image processing, and image averaging. For intensity detection, the precision limit of the SPR is around 10–5 RIU to 10–6 RIU. Here, we propose a deep learning-based method to locate the plasmonic angle to enhance plasmonic angle detection without needing sophisticated post-processing, optical instrumentation, and polynomial curve fitting methods. The proposed deep learning has been developed based on a simple convolutional neural network architecture and trained using simulated reflectance spectra with shot noise and speckle noise added to generalize the training dataset. The proposed network has been validated in an experimental setup measuring air and nitrogen gas refractive indices at different concentrations. The measurement precision recovered from the experimental reflectance images is 4.23 × 10–6 RIU for the proposed artificial intelligence-based method compared to 7.03 × 10–6 RIU for the cubic polynomial curve fitting and 5.59 × 10–6 RIU for 2-dimensional contour fitting using Horner's method.

Optical biosensor based on enhanced surface plasmon resonance: theoretical optimization

In this article, a theoretical design of enhanced surface plasmon resonance is proposed. The suggested sensor is composed of titanium, silver, graphene, photonic crystal, and a sensing layer. This structure is used to detect cancer cells and hemoglobin in blood plasma based on their refractive indices. Different parameters such as sensitivity and figure of merit are studied at an operating wavelength of 633 nm. The recorded sensitivity and figure of merit are 72 degrees/RIU and 346 RIU−1. The ability of the proposed sensor to detect cancer cells and blood plasma concentration will be investigated.

Epitaxial Engineering Strategy to Amplify Localized Surface Plasmon Resonance and Electrocatalytic Activity Enhancement in Layered Bismuth Selenide by Phosphorus Functionalization

AbstractBismuth selenide (Bi2Se3) is an orderly layered material with large surface area and localized surface plasmon resonance (LSPR). The electrocatalytic profile of Bi2Se3 has been least explore for energy storage applications since its pristine form is handicapped with limited electrical conductivity. Here we report an epitaxial engineering strategy to manipulate the weak van der Waals forces to expand the interlayer spacing by intercalating phosphorus (P) atom by chemical vapor deposition (CVD) method. The obtained P intercalated Bi2Se3 (P@Bi2Se3) exhibited towering LSPR, increased carrier density bestowing ample active sites, enhanced ion diffusion and plentiful channels for the exodus of electrolyte. The potential of P@Bi2Se3 was examined for energy storage application which exhibited battery like behavior with a specific capacity (Cs) of 194 C g−1 at 3 A g−1 current density against 121 C g−1 by Bi2Se3/NF under identical condition and restored 88 % of its initial specific capacity even after 5000 charge/discharge cycles. The hybrid supercapacitor (HSC) assembled using P@Bi2Se3 and O, N, S@AC as positive and negative electrodes exhibited a considerable specific capacitance, high specific energy (Es) and specific power (Ps) with excellent stability for 10000 charge/discharge cycles. The surface and interfacial engineering strategy proposed here can be extended to tune plasmonic resonance and charge carrier energy density for the successful implementation of Bi2Se3 beyond energy storage applications.

Dye random laser enhanced by graphene-based Au nanoparticles

The graphene and nanoparticles composites have novel optical and electrical properties. They are widely used in the fields of information sensing, photoelectric conversion and medical diagnosis. Graphene has excellent photoelectric properties and can regulate the random laser properties, but the current composite process of graphene with special structures and metal nanostructures is complicated. Thus, there is still a challenge to effectively reducing the threshold of random laser by using graphene. In this work, the Au/graphene structure is prepared by convenient chemical reduction and adsorption method, and the dye DCJTB is used as the gain medium to form the film by spin coating. The random laser properties of Au nanoparticles and Au/graphene structure are studied, and the mechanism of graphene is analyzed. The results show that the transmission peak of Au/graphene composite is near the photoluminescence peak of gain medium, which promotes the energy level transition of dye molecules. With the addition of graphene into the same gain medium, the scattering frequency of photons in the disordered medium increases, resulting in the enhancement of surface plasmon resonance. The scattering effect and the surface plasmon resonance effect cooperate with each other, showing good random laser threshold, which is reduced from 3.4 μJ/mm<sup>2</sup> to 2.8 μJ/mm<sup>2</sup>. Repeatability and high quality of maser are obtained by repetitively measuring the same sample, showing that the lasing sample has good repeatability and high quality. This study plays a certain role in promoting the application of random laser and realizing the high-performance optoelectronic devices.

High Sensitivity Coreless Fiber Surface Plasmon Resonance Sensor Based on Au Nano Biconical Particles

A coupling enhanced surface plasmon resonance (SPR) sensor based on coreless fiber is proposed. Compared with the common fiber, the coreless fiber is easier to perceive the changes of the external medium environment. As one-dimensional material with superior performance, the Au nano biconical particles are used to improve the sensor performance. Based on the finite element method (FEM), the electric field enhancement effect of the coupling between the SPR of the gold film and the Localized surface plasmon resonance (LSPR) of the Au nano biconical particles on the surface of the coreless fiber is analyzed, and the experimental results show that the Au nano biconical particles can improve the sensitivity. The sensitivity of the improved Au nano biconical particle sensor is 3514 nm/RIU, which is 64% higher than that of the traditional gold film SPR sensor, and the quality factor is increased by 24%. The new sensor based on Au nano biconical particles and gold film has a good application prospect in biosensor and chemical measurement.

Carboxymethyl chitosan/graphene oxide/silver nanotriangles nanohybrid as the sensing materials for the enhancement of ammonia localized surface plasmon resonance sensor

This work reports the application of silver nanotriangles (AgNT) incorporated with chitosan/graphene oxide (Chit/GO) and carboxymethyl chitosan/graphene oxide (CMChit/GO) for the enhancement of ammonium localized surface plasmon resonance (SPR) sensor. The ammonium is detected through the hydrogen bonding between the hydroxyl functional group on the sensing material surface with ammonium. AgNT was successfully synthesized via the direct chemical reduction method. The appearance of three peaks in UV–visible analysis, 334, 486 and 677 nm corresponded to the out of plane quadrupole resonance, anisotropic nanoparticles, and in-plane dipole resonance formations, respectively. The morphology analysis by FESEM exhibits that the AgNT has a diameter of 45.16 nm. Zeta analysis depicts the average size distribution and surface potential of AgNT with 16.53 d.nm and −34.5 mV, respectively. Meanwhile, Chit/GO derivatives were synthesized via the solution mixing method. The AFM analysis resulted in the surface roughness for Chit/GO and CMChit/GO with 28.65 nm and 20.43, respectively, due to the abundance of electronegative groups on their surface, which provides more active sites for ammonium attachment. Chit/GO and CMChit/GO were incorporated with AgNT before the sensor performance analysis. In localized SPR sensing, Chit/GO/AgNT and CMChit/GO/AgNT exhibit the sensitivity of 0.39 and 2.41 nm ppm−1, respectively.

MoS2 Nanodonuts for High-Sensitivity Surface-Enhanced Raman Spectroscopy.

Nanohybrids of graphene and two-dimensional (2D) layered transition metal dichalcogenides (TMD) nanostructures can provide a promising substrate for extraordinary surface-enhanced Raman spectroscopy (SERS) due to the combined electromagnetic enhancement on TMD nanostructures via localized surface plasmonic resonance (LSPR) and chemical enhancement on graphene. In these nanohybrid SERS substrates, the LSPR on TMD nanostructures is affected by the TMD morphology. Herein, we report the first successful growth of MoS2 nanodonuts (N-donuts) on graphene using a vapor transport process on graphene. Using Rhodamine 6G (R6G) as a probe, SERS spectra were compared on MoS2 N-donuts/graphene nanohybrids substrates. A remarkably high R6G SERS sensitivity up to 2 × 10−12 M has been obtained, which can be attributed to the more robust LSPR effect than in other TMD nanostructures such as nanodiscs as suggested by the finite-difference time-domain simulation. This result demonstrates that non-metallic TMD/graphene nanohybrids substrates can have SERS sensitivity up to one order of magnitude higher than that reported on the plasmonic metal nanostructures/2D materials SERS substrates, providing a promising scheme for high-sensitivity, low-cost applications for biosensing.

Porous graphdiyne loading CoOx quantum dots for fixation nitrogen reaction

Over the years, scientists have sought to pursue ammonia (NH 3 ) production, and have tried to bring huge transform and benefits for renewable energy technologies to replace high-pollution and energy-consuming Haber-Bosh processes. Here we would like to launch a novel catalyst of porous graphdiyne (GDY) based quantum dots for ammonia production. The ultra-high catalytic performance is origin from the rapid conversion of valence states of metal element within the catalyst and the great enhancement of surface plasmon resonance (SPR). This highly compatible synergistic effect enables excellent photocatalytic performance. After 46 independent experiments, a highest NH 3 yield rate (Y NH3 ) of 26502 μmol NH3 g cat. −1 h −1 , a lowest Y NH3 of 15026 μmol NH3 g cat. −1 h −1 , and an average Y NH3 of 19583 μmol NH3 g cat. −1 h −1 in 46 independent experiments were respectively given, as well as the high long-term stability. A novel catalyst of porous graphdiyne (GDY) based quantum dots was precisely synthesized for photocatalyzed ammonia production. The strong advantages of graphdiyne could effectively regulate photocatalytic activity and coordination environments and great enhance the surface plasmon resonance (SPR) effect, which enables excellent NH 3 yield rate and high long-term stability. • A novel catalyst of porous graphdiyne based quantum dots was precisely synthesized for photocatalyzed ammonia production. • Graphdiyne effectively regulates the coordination environments and the surface plasmon resonance effect of the catalysts. • The unique properties of the catalyst endow it with excellent NH3 yield rate and high long-term stability.

Plasmonic enhancement of hydrogen production by water splitting with CdS nanowires protected by metallic TiN overlayers as highly efficient photocatalysts

A novel CdS/TiN core-shell structure has been synthesized to produce the hydrogen gas in the photocatalytic water splitting (PWS) with sacrificial agents under simulated solar light (AM 1.5G). The single-crystalline and high-aspect-ratio CdS nanowires (NWs) are coated with different thicknesses of TiN layer. In particular, the CdS NWs with a thickness of 15-nm TiN showed the best performance in hydrogen production that can improve the hydrogen production rate by about 362% compared to the CdS NWs. In the meantime, it can avoid the detrimental issues regarding the use of CdS alone such as low stability and release of toxic component. This significant improvement of the TiN outer layer is a synergetic effect of three main factors, including the improvement of light absorption and electron concentration caused by surface plasmon resonance (SPR) enhancement effect, the reduction of the possibility of photo-induced carrier recombination, and the outstanding chemical stability during photocatalytic water splitting. In addition, the effects of protective TiN layer on the electric fields generated by light irradiance on the system have been calculated and simulated with the finite-difference time-domain (FDTD) method. The results are consistent with the proposed mechanism for best performance with plasmonic enhancement. The work represents a significant advance in the production of hydrogen via photocatalytic water splitting.

Hierarchically assembled silver nanoprism-graphene oxide-silicon nanowire arrays for ultrasensitive surface enhanced Raman spectroscopy sensing of atrazine

Exploration of novel strategies for fabricating SERS substrates attracted enormous research potential as achieving high sensitivity, reproducibility along with cost effectiveness is really challenging. Herein, we have fabricated hierarchical silver nanoprism/graphene oxide/silicon nanowire (Ag/GO/SiNWs) arrays as surface-enhanced Raman scattering (SERS) sensors for the effective detection of atrazine. Homogenous and vertically aligned SiNWs have been successfully synthesized using silver assisted chemical etching. Further, Ag/GO/SiNWs arrays were assembled by subsequent spin-coating of GO followed by drop-casting deposition of Ag nanoprisms. Micro-structural properties of as-fabricated nano-arrays have been well examined by scanning electron and atomic force microscopic techniques. Nanowire bunches have been decorated by GO layers; which further facilitates homogenous deposition of Ag nanoprisms. Using rhodamin 6G as probe molecule, high SERS activity and excellent reproducibility of as-fabricated substrates have been demonstrated. High efficiency of 3.2 × 108 and was obtained for the fabricated sensors; attributed to the synergetic charge transfer between GO and Ag nanoprisms on high surface area Si nanowires. Charge transfer mechanism that leading to enhanced surface plasmon resonance effect of the as-fabricated array was established as well. Further, these low cost Ag/GO/SiNWs sensors exhibited ultrasensitive detection of pollutants such as methylene blue and atrazine residues down to picomolar levels; these can serve as potential chemical sensors for rapid monitoring of environmental pollutants in trace levels.

Enhanced surface plasmon resonance in gold nanoparticles dewetted on monolayer hexagonal boron nitride

In this paper, the effect of dewetted gold nanoparticles (AuNPs) on hexagonal boron nitride (hBN) is discussed along with the changes in surface plasmon resonance (SPR). Au is sputtered on monolayer hBN/SiO2/Si substrate for a varied duration and subjected to thermal annealing. Monolayer hBN is verified by spectroscopic ellipsometry using the Tauc–Lorentz model, while the AuNPs are modeled using a combination of Gauss, Cody–Lorentz, and Tanguy dispersion laws. Sputtering of Au on hBN/SiO2/Si results in a film-like layer compared to the one on SiO2/Si. Before annealing, the improved uniformity of Au on hBN/SiO2/Si diminished the SPR wavelength, [Formula: see text], when the sputter duration exceeded 30 s, much sooner compared to 120 s from the one on SiO2/Si. After annealing, the [Formula: see text] is vibrant for all samples around 2.3 eV. Au dewetted more on hBN due to higher surface tension. Large dewetted AuNPs supported by hBN result in higher photon extinction at [Formula: see text]. The longest sputter duration of 120 s on hBN/SiO2/Si (mean size 53 nm) exhibited an 11.2% higher extinction coefficient compared to the one on SiO2/Si (mean size 39.6 nm). Findings support the advantages of preparing plasmonic AuNPs by dewetting on monolayer hBN.