Au Film Research Articles

Orientation-dependent two-dimensional magnonic crystal modes in an ultralow-damping ferrimagnetic waveguide containing repositioned hexagonal lattices of Cu disks

Two-dimensional (2D) hexagonal lattices of Cu disks are shown to induce orientation-dependent magnonic crystal (MC) modes for propagating forward volume spin waves in a single-crystal yttrium iron garnet (YIG) film. The width and depth of the magnonic band gaps are 0.022 GHz and –15.2 dB at the frequency of 1.815 GHz. Integrating differently oriented lattices on the same YIG film and positioning them between the microwave antenna surrounded by magnon absorbers consisting of Au films, we clearly resolve a characteristic frequency shift of the magnonic band gap by altering the incident angle of the spin waves to the 2D MC. The shift amounts to approximately 10 MHz when the incident angle is changed between 10° and 30°. The obtained results show a good agreement with calculations using the finite integration technique and are a step toward complete band-gap investigations in YIG of ultralow spin-wave damping. Published by the American Physical Society 2024

Tip-based Lithography with a Sacrificial Layer.

The fabrication of a highly controlled gold (Au) nanohole (NH) array via tip-based lithography is improved by incorporating a sacrificial layer-a tip-crash buffer layer. This inclusion mitigates scratches during the nano-indentation process by employing a 300nm thick poly(methyl methacrylate) layer as a sacrificial layer on top of the Au film. Such a precaution ensures minimal scratches on the Au film, facilitating the creation of sub-50nm Au NHs with a 15nm gap between the Au NHs. The precision of this method exceeds that of fabricating Au NHs without a sacrificial layer. Demonstrating its versatility, this Au NH array is utilized in two distinct applications: as a dry etching mask to form a molybdenum disulfide hole array and as a catalyst in metal-assisted chemical etching, resulting in conical-shaped silicon nanostructures. Additionally, a significant electric field is generated when Au nanoparticles (NPs) are placed within the Au NHs. This effect arises from coupling electromagnetic waves, concentrated by the Au NHs and amplified by the Au NPs. A notable result of this configuration is the enhancement factor of surface-enhanced Raman scattering, which is an order of magnitude greater than that observed with just Au NHs and Au NPs alone.

A study on the Raman response of TiO2 upon ion-implantation and annealing in O2 atmosphere

The doped TiO2 materials exhibit extraordinary opto-electronic properties and in this regard, Ion-Implantation process offers extreme control and flexibility to fabricate such materials. In this work, it is shown that the electronic structure, optical absorption and raman response of TiO2 to be modified by single ion and sequential implantation process with Ag− (65 KeV), Au− (80 KeV) ions and post-implantation annealing at 450 °C for an hour in O2 atmosphere. The raman spectra of implanted and implanted/annealed TiO2 films depict anatase phase characteristics and implantation-induced effects are believed to alter the crystallinity in these materials. The sequentially implanted films Au_Ag_1 × 1016/TiO2, Au_Ag_1.5 × 1016/TiO2 depict an additional band at 65 cm−1 prior to Eg(1) band at 144.35 cm−1 and are further bettered upon annealing. The absorbance of the implanted TiO2 films is increased in the visible spectral region when compared to pristine TiO2 and are further enhanced upon annealing. The film Au_Ag_1 × 1016/TiO2 (A) exhibited optical band gap ∼2.96 eV when compared to 3.13 eV of pristine TiO2 and these materials with modified optical properties have implications for Photocatalysis, Photo-electrochemical water-splitting and Photovoltaic applications.

Dewetting upside-down: two-sided solid state dewetting of thin gold film on soft KBr substrate

Abstract We deposited a 30 nm-thick Au film on single crystalline KBr substrate and studied the solid state dewetting behavior of the film at a temperature of 350 °C. At this temperature, the ions of the KBr compound exhibit significant mobility along the Au–KBr interface, which affects the morphology and kinetics of the solid state dewetting. We performed statistical morphology analysis of the Au–KBr interface by selectively dissolving the KBr substrate after the dewetting heat treatments and subsequent atomic force microscopy imaging of the “upside-down” oriented Au film. We demonstrated that atomic mobility at the interface leads to embedding of the partially dewetted Au film into the KBr substrate. We proposed a quantitative model of the shape evolution of a disc-shaped Au particle on the KBr substrate under the condition of finite interface mobility of the substrate species. The model predictions were consistent with the experimentally observed sinking rates of Au nanostructures.

Scalable hot carrier–assisted silicon photodetector array based on ultrathin gold film

Abstract Silicon (Si) offers cost-effective production and convenient on-chip integration for photodetection due to its well-established CMOS technology. However, the indirect bandgap of Si inherently limits its detection efficiency in the near-infrared (NIR) regime. Here, we propose a strategy to achieve high NIR photoresponse in Si by introducing a strong light-absorbing ultrathin gold (Au) film to generate hot carriers. Using a 4.6 nm thick-Au film deposited on Si, we achieved photoresponsivity of 1.6 mA/W at 1310 nm under zero-bias conditions, and rapid temporal responses of 7.5 and 8 μs for rise and fall times, respectively, comparable to germanium (Ge) photodiodes. By utilizing an ultrathin (<6 nm) Au film as the light-detecting layer and thicker (>100 nm) Au film as electrodes, we introduce a unique approach to design a photodiode array based on a single metal (Au) platform. Comparative analysis with a commercial beam profiler image validates the performance of our designed array. This work presents an efficient strategy for manufacturing cost-effective and scalable NIR photodetector arrays, which eliminates the need for additional insulator layers.

Simultaneous Surface-Enhanced Raman Scattering with a Kerr Gate for Fluorescence Suppression.

The combination of surface-enhanced and Kerr-gated Raman spectroscopy for the enhancement of the Raman signal and suppression of fluorescence is reported. Surface-enhanced Raman scattering (SERS)-active gold substrates were demonstrated for the expansion of the surface generality of optical Kerr-gated Raman spectroscopy, broadening its applicability to the study of analytes that show a weak Raman signal in highly fluorescent media under (pre)resonant conditions. This approach is highlighted by the well-defined spectra of rhodamine 6G, Nile red, and Nile blue. The Raman spectra of fluorescent dyes were obtained only when SERS-active substrates were used in combination with the Kerr gate. To achieve enhancement of the weaker Raman scattering, Au films with different roughnesses or Au-core-shell-isolated nanoparticles (SHINs) were used. The use of SHINs enabled measurement of fluorescent dyes on non-SERS-active, optically flat Au, Cu, and Al substrates.

Emergent Dirac Fermions in Epitaxial Planar Silicene Heterostructure.

Silicene, a single layer of Si atoms, shares many remarkable electronic properties with graphene. So far, silicene has been synthesized in its epitaxial form on a few surfaces of solids. Thus, the problem of silicene-substrate interaction appears, which usually depresses the original electronic behavior but may trigger properties superior to those of bare components. We report the direct observation of robust Dirac-dispersed bands in epitaxial silicene grown on Au(111) films deposited on Si(111). By performing in-depth angle-resolved photoemission spectroscopy measurements, we reveal three pairs of one-dimensional bands with linear dispersion running in three different directions of an otherwise two-dimensional system. By combining these results with first-principles calculations, we explore the nature of these bands and point to strong interaction between subsystems forming a complex Si-Au heterostructure. These findings emphasize the essential role of interfacial coupling and open a unique materials platform for exploring exotic quantum phenomena and applications in future-generation nanoelectronics.

Direct Characterization of Buried Interfaces in 2D/3D Heterostructures Enabled by GeO2 Release Layer.

Inconsistent interface control in devices based on two-dimensional materials (2DMs) has limited technological maturation. Astounding variability of 2D/three-dimensional (2D/3D) interface properties has been reported, which has been exacerbated by the lack of direct investigations of buried interfaces commonly found in devices. Herein, we demonstrate a new process that enables the assembly and isolation of device-relevant heterostructures for buried interface characterization. This is achieved by implementing a water-soluble substrate (GeO2), which enables deposition of many materials onto the 2DM and subsequent heterostructure release by dissolving the GeO2 substrate. Here, we utilize this novel approach to compare how the chemistry, doping, and strain in monolayer MoS2 heterostructures fabricated by direct deposition vary from those fabricated by transfer techniques to show how interface properties differ with the heterostructure fabrication method. Direct deposition of thick Ni and Ti films is found to react with the monolayer MoS2. These interface reactions convert 50% of MoS2 into intermetallic species, which greatly exceeds the 10% conversion reported previously and 0% observed in transfer-fabricated heterostructures. We also measure notable differences in MoS2 carrier concentration depending on the heterostructure fabrication method. Direct deposition of thick Au, Ni, and Al2O3 films onto MoS2 increases the hole concentration by >1012 cm-2 compared to heterostructures fabricated by transferring MoS2 onto these materials. Thus, we demonstrate a universal method to fabricate 2D/3D heterostructures and expose buried interfaces for direct characterization.

Tunable formation of gold nanoparticles on polymer by keV ion beam irradiation

The formation of nanostructures from a thin Au film deposited on a polystyrene and polymethylmethacrylate substrate under keV monatomic P, Ta and molecular PF4 ion irradiation is studied. The formation of nanoparticles on both kinds of polymers is shown. Heavy Ta ions are most effective in altering the Au layer, whereas its transformation by light P or molecular PF4 ions is less pronounced. Irradiation with PF4 ions has a much smaller effect on the PS and PMMA substrate bulk compared to that with monatomic P ions. The crucial role of collision cascade density in the process of thin metallic film coagulation on polymer substrate is revealed. During ion bombardment, transmitted IR light intensity increases proportionally to the area covered by the metal film, which makes it possible to use FTIR as a rapid technique to estimate the state of the nanoparticle formation process.

Tailoring group delay dispersion of surface plasmon polaritons propagating on thin gold film by chirped femtosecond laser pulses

Understanding the propagation characteristics of surface plasmon polaritons (SPPs) is of great significance in designing and constructing on-chip integrated systems utilizing plasmonic effect. Accurately characterizing and flexibly controlling SPP on thin metal film are indispensable. Here, we theoretically derive the group velocity dispersion of SPP propagation on the surface of Au films with various thicknesses. The results obtained in this work indicate that when the thickness of the Au film is less than 40 nm, group velocity dispersion of SPP decreases significantly as the film thickness increases. The decrease of group velocity dispersion becomes mild with the thickness increasing from 40 nm to 60 nm, then the dispersion keeps a very low constant value for the film thicker than 60 nm. Using the finite-difference time-domain method, temporal evolution of localized electric field of SPP is numerically simulated for various propagation distances. By comparing the field amplitudes and the dispersions of SPP which are excited by incident light pulses with different dispersions, group velocity dispersions of SPP on the Au films are obtained, showing a good consistence with the theoretical results. Moreover, we demonstrate that by utilizing the tailored SPP to excite metal nanoantenna, selective excitations at different frequencies on a femtosecond temporal scale can be achieved through localized surface plasmonic resonant effect. Manipulating the sign and amount of the dispersion from the incident pulse, the active control of the switching sequence and switching time of electric field between the Au cylinders can be achieved. Manipulating the propagation distance of SPP, the active control of the switching time of electric field between the Au cylinders can be achieved. Therefore, those results provide a promising avenue for realizing functions such as signal propagation, reception, adjustment, and encoding in on-chip interconnect circuit systems based on SPP. This work shows that the dispersion can be used as degree of freedom for controlling the amplitude, phase and pulse width of SPP propagating on thin film, and it is of great importance in designing and controlling on-chip integrated systems through utilizing plasmonic effect, such as ultrafast frequency demodulators and nanoantennas in on-chip interconnect optical circuits.

Towards the epitaxial growth of Au thin films on MgO substrates for plasmonic applications

Surface Plasmon Polaritons (SPPs) in Au thin films are nowadays intensively exploited for sensing applications that leverage the strong optical field confinement at the metal/dielectric interface and the easy functionalization of the Au surface. Moreover, Au thin films represent one of the common starting points for the top-down nanofabrication of plasmonic nanostructures supporting localized resonances. In this framework, strategies for the growth of high-quality Au films on transparent substrates are crucial and not yet fully established. In this study, we exploit MgO(001) substrates for the growth of thin (about 45 nm) Au films, also including an additional buffer layer of Fe. We successfully demonstrate Au samples with reduced roughness and presenting Low-Energy Electron Diffraction (LEED) features, indicating a high degree of crystalline ordering. This is supported by the experimental evidence of an increased (by almost a factor of 3) propagation length compared to a reference Au sample grown on standard glass slides, which is however still significantly lower than the one expected from first principles.

Advanced Integration of Glutathione-Functionalized Optical Fiber SPR Sensor for Ultra-Sensitive Detection of Lead Ions.

It is crucial to detect Pb2+ accurately and rapidly. This work proposes an ultra-sensitive optical fiber surface plasmon resonance (SPR) sensor functionalized with glutathione (GSH) for label-free detection of the ultra-low Pb2+ concentration, in which the refractive index (RI) sensitivity of the multimode-singlemode-multimode (MSM) hetero-core fiber is largely enhanced by the gold nanoparticles (AuNPs)/Au film coupling SPR effect. The GSH is modified on the fiber as the sensing probe to capture and identify Pb2+ specifically. Its working principle is that the Pb2+ chemically reacts with deprotonated carboxyl groups in GSH through ligand bonding, resulting in the formation of stable and specific chelates, inducing the variation of the local RI on the sensor surface, which in turn leads to the SPR wavelength shift in the transmission spectrum. Attributing to the AuNPs, both the Au substrates can be fully functionalized with the GSH molecules as the probes, which largely increases the number of active sites for Pb2+ trapping. Combined with the SPR effect, the sensor achieves a sensitivity of 2.32 × 1011 nm/M and a limit of detection (LOD) of 0.43 pM. It also demonstrates exceptional specificity, stability, and reproducibility, making it suitable for various applications in water pollution, biomedicine, and food safety.

Crystal Lattice Rearrangement Occurred at Au/Ag Bonded Interface in Atomic Diffusion Bonding in Vacuum

Atomic diffusion bonding (ADB) processing of wafers using thin metal films is a promising route to achieving room-temperature wafer bonding [1,2]. When two film surfaces mutually contact at room temperature during ADB, crystal lattice rearrangement occurs, thereby enhancing the bonding performance. Generally, films of the same material used for bonding are fabricated on two flat wafer surfaces. Therefore, methods for examining the crystal lattice rearrangement mechanism are few. Two representative material films used for bonding, those of the metals Au and Ag, have fcc crystal structure and show a solid solution in the whole Au–Ag composition range. Moreover, lattice mismatch of these materials is very slight: less than 0.2%. For this study, Au film and Ag film were bonded in vacuum using ADB. The crystallographic structure of Au/Ag bonded films and depth profiles of Au and Ag atoms were examined. Au and Ag films were fabricated respectively on two flat wafer surfaces using sputter deposition, followed by bonding of the two films on the wafers in vacuum. Figure 1 portrays cross-section STEM images of Au(20 nm)/Ag(20 nm) bonded films: (A) a bright field image, and (B) an HAADF image corresponding to (A). Films were deposited on Si wafers, with 5-nm-thick Ta films underneath. Figure 1(A) shows that no interface corresponding to the original Au/Ag interface is visible; no vacancy is observed. Grains were formed continuously across the original interface over the entire thickness of the bonded films, indicating that crystal lattice rearrangement occurred at room temperature when the films mutually contacted in vacuum. Although the crystallographic structures of Au and Ag layers are identical because of the crystal lattice rearrangement, the contrast between the upper and lower half areas in Figure 1(B) is expected to be attributable mainly to the different atomic weights of Au and Ag. Figure 2 presents the depth profiles of Au, Ag, and Ta evaluated using EELS analysis along line (a) in Figure 1(B). Results supported that interdiffusion at the Au/Ag bonded interface is not remarkable. This report presents discussion of the relation between crystal lattice rearrangement and interdiffusion of atoms based on results of analyses of Au/Ag bonded films with various layer structures. T. Shimatsu and M. Uomoto, J. Vac. Sci. Technol., B 28, 706 (2010).T. Shimatsu and M. Uomoto, ECS Trans., 33 (4), 61 (2010). Figure 1

Solid-State Dewetting of Thin Au Films for Surface Functionalization of Biomedical Implants.

Biomaterial-centered infections of orthopedic implants remain a significant burden in the healthcare system due to sedentary lifestyles and an aging population. One approach to combat infections and improve implant osteointegration is functionalizing the implant surface with anti-infective and osteoinductive agents. In this framework, Au nanoparticles are produced on the surface of Ti-6Al-4V medical alloy by solid-state dewetting of 5 nm Au film and used as the substrate for the conjugation of a model antibiotic vancomycin via a mono-thiolated poly(ethylene glycol) linker. Produced Au nanoparticles on Ti-6Al-4V surface are equiaxed with a mean diameter 19.8 ± 7.2 nm, which is shown by high-resolution scanning electron microscopy and atomic force microscopy. The conjugation of the antibiotic vancomycin, 18.8 ± 1.3 nm-thick film, is confirmed by high resolution-scanning transmission electron microscopy and X-ray photoelectron spectroscopy. Overall, showing a link between the solid-state dewetting process and surface functionalization, we demonstrate a novel, simple, and versatile method for functionalization of implant surfaces.

Ultrafast dynamics and ablation mechanism in femtosecond laser irradiated Au/Ti bilayer systems

Abstract The significance of ultrafast laser-induced energy and mass transfer at interfaces has been growing in the field of nanoscience and technology. Nevertheless, the complexity arising from non-linear and non-equilibrium optical-thermal-mechanical interactions results in intricate transitional behaviors. This complexity presents challenges when attempting to analyze these phenomena exclusively through modeling or experimentation. In this study, we conduct time-resolved reflective pump-probe imaging and molecular-dynamics coupled two-temperature model (MD-TTM) simulations to investigate the ultrafast dynamics and ablation mechanism of Au/Ti bilayer systems. The calculated energy absorption curves indicate that Au film reduces the energy deposition in the underlying Ti layer, resulting in reduced melting and evaporation rate of Ti. The phase transition process induces different mechanical responses. The potential energy patterns indicate that the expansion of vapor Ti extrudes the surface Au layer outward. In simulated stress distribution images, the Au layer can hamper the expansion of the vapor-phase Ti and brings dynamic compressive stress to the residual Ti layer. When the compressive stress transforms into tensile stress, the material is removed through mechanical damage. Therefore, both Au and Ti in the 20 nm Au-covered Ti are completely removed. Our approach elucidates the ablation mechanism within the Au/Ti bilayer system and offers fresh insights into managing thermo-mechanical responses within analogous systems.

Manipulating the Exciton Dynamics in a MoS2/WS2 Heterobilayer with a Si/Au Nanocavity

AbstractManipulating the exciton dynamics in a heterobilayer (HB) composed of two transition metal dichalcogenides (TMDCs) is important in the development of photonic/plasmonic devices based on TMDC HBs. Here, the realization of such a manipulation in a MoS2/WS2 HB is reported by using a Si/Au hybrid nanocavity composed of a Si nanoparticle and an Au film, which is manifested in the modification in the photoluminescence (PL) of the embedded MoS2/WS2 HB. It is shown that a transition from PL quenching to PL enhancement can be achieved by adjusting the diameter of the Si nanoparticle, which modifies the plasmon resonance supported by the Si/Au nanocavity. More interestingly, it is demonstrated that the enhancement factor can be manipulated by shifting the exciton/trion resonance close to or far away from the plasmon resonance by simply increasing the laser power. It is revealed that the manipulation is realized by effectively controlling the strain and Purcell effects induced by the Si/Au nanocavity. A PL enhancement factor as large as ≈187 in the MoS2/WS2 HB at a high laser power is observed. The findings suggest the potential applications of dielectric‐metal hybrid nanocavities in the manipulation of the exciton dynamics in TMDC HBs and the development of novel plasmonic devices.

An in-fiber sensor for simultaneous measurement of cholesterol concentration and temperature based on SPR and MMI

In this paper, we design an in-fiber two-parameter sensor with multimode fiber (MMF)-Au film coated hollow fiber (HCF)-MMF structure, which can simultaneously excite Surface Plasmon Resonance (SPR) effect and Multimode Interference (MMI) effect. A composite material of Au nanoparticles/β-cyclodextrin (AuNPs/β-CD) is deposited on the surface of the Au film coated HCF to realize highly-sensitive measurement of cholesterol concentration. Here, the AuNPs can not only enhance the measurement sensitivity of the SPR sensor, but also increase the numbers of combination sites of β-CD and cholesterol. Then, to solve the cross-sensitivity problem between temperature and cholesterol, the glycerin is selected as a temperature-sensitive material to fill into the inner channel of the HCF, making the MMI sensor sensitive to temperature, and finally realizing the simultaneous measurement of cholesterol concentration and temperature. The experimental results demonstrate that the wavelength shift of the SPR and the MMI are 12.7 nm and 7.9 nm, respectively, when the cholesterol concentration changes from 0 to 500 nM. The temperature sensitivity of the SPR and the MMI are −0.9 nm/°C and 2.64 nm/°C, respectively, in the temperature range of 30°C–46 °C. In addition, the sensor shows good recognition ability of cholesterol molecules in serum environment, with good stability, selectivity and repeatability, and has broad application prospects in the biomedical field.

Electrically tunable and switchable perfect infrared absorber based on ENZ material

In this paper, a dynamically tunable and switchable perfect infrared absorber is put forward, which is composed of a gold ring array, an indium tin oxide (ITO) layer, an alumina (Al2O3) spacer and a continuous Au film from top to bottom. Epsilon-near-zero (ENZ) mode in ITO layer is excited by localized surface plasmon resonance (LSPR) mode of the gold ring. With the increase of the biasing voltage V, the carrier concentration of ITO material decreases, and the absorption peak caused by ENZ resonance blue shifts obviously. Notice that our infrared absorber can realize bidirectional switching of “ON” and “OFF” states at 1210 nm, with modulation depth of 70 % and switching contrast (SC) of 241 %, manifesting its excellent electrical regulation performance. After verification, the switching performance of our absorption structure has a high precision tolerate of the manufacturing process. A clear Fano type absorption curve appears in the wavelength range 1000 nm–1300 nm, under the biasing voltage V of 3.4 V. Moreover, a series of small absorption peaks are produced by Fabry-Pérot (F–P) resonance in the horizontal plane caused by the standing wave in the ENZ layer, and this phenomenon is unexpected. We propose a theoretical interpretation for the absorption mechanism in both cases based on multiple interference model. It is also proved that the proposed infrared absorber is polarization insensitive and exhibits high absorptance (>90 %) over an incident range of 0 deg–60 deg. The electrically tunable absorption switch function makes our absorber have potential in selective thermal emitters, infrared sensors, infrared stealth, beam focusing and other fields.

Purposive Design of Stretchable Composite Electrodes for Strain-Negative, Strain-Neutral, and Strain-Positive Ionic Sensors.

Soft ionic sensors have emerged as a promising device form to accommodate various future electronic applications. One of the hurdles in ionic sensors is that the sensing signals by mechanical deformation and other stimuli are mixed up. Although the performance of the ionic sensors is highly dependent on the structure of electrodes, systematic investigation of purposive electrode design has been rarely explored. This study proposes a simple strategy for designing stretchable composite electrodes which make the ionic sensor strain-negative, strain-neutral, and strain-positive. This study reveals that such strain-responses can be obtained by adjusting the surface coverage of the electrically-effective conductive fillers. On the basis of the concept, deposition of a Au film on an elastomer composite and crack formation of the Au film are presented for the practical fabrication of a highly reproducible strain-neutral ionic sensor. A completely strain-independent temperature sensor is demonstrated by using the Au crack-based ionic sensor. In addition, this study demonstrates a two-terminal shear sensor capable of recognizing shear directions by combining the strain-positive and strain-negative electrodes.

Surface Functionalization and Escherichia coli Detection Using Surface-Enhanced Raman Spectroscopy Driven by Functional Organic Polymer/Gold Nanofilm-Based Microfluidic Chip.

In this work, a microfluidic prototype based on polymeric materials was developed to monitor surface processes using surface-enhanced Raman spectroscopy (SERS), keeping the reagents free of environmental contamination. The prototype was fabricated on poly(methyl methacrylic acid) (PMMA). A micrometric membrane of a functional organic polymer (FOP) based on p-terphenyl and bromopyruvic acid monomers was formed on the PMMA surface to promote the formation of metal nanoclusters. Au nanosized film was deposited on the FOP membrane to give rise to the SERS effect. A microchannel was formed on another piece of PMMA using micromachining. A representative 3D model of the prototype layer arrangement was built and simulated in COMSOL Multiphysics® to approximate the electric field distribution and calculate the power enhancement factor as the Au film changes over time. The fabrication process was characterized using UV-visible and Raman spectroscopies and XPS. The prototype was tested using a Raman microscope and liquid solutions of cysteamine and Escherichia coli (E. coli). The simulation results demonstrated that the morphological characteristics of the Au layer give rise to the SERS effect, and the power enhancement factor reaches values as high as 8.8 × 105 on the FOP surface. The characterization results showed the formation of the FOP and the Au film on PMMA and the surface functionalization with amine groups. The Raman spectra of the prototype showed temporal evolution as different compounds were deposited on the upper wall of the microchannel. Characteristic peaks associated with these compounds were detected with continuous monitoring over time. This prototype offers many benefits for applications like monitoring biological processes. Some advantages include timely surface evaluation while avoiding environmental harm, decreased use of reagents and samples, minimal interference with the process by measuring, and detecting microorganisms in just 1 h, as demonstrated with the E. coli sample.