Fabricating Silver Nanostructure Arrays with Laser Assisted Process for Nano Plastic Detection

Candra, Muhammad Fajri (2026) Fabricating Silver Nanostructure Arrays with Laser Assisted Process for Nano Plastic Detection. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Surface-enhanced Raman scattering (SERS) merupakan teknik analisis yang mampu mendeteksi analit berkonsentrasi rendah melalui penguatan sinyal Raman oleh nanostruktur plasmonik. Dalam penelitian ini, nanostruktur perak difabrikasi pada substrat kaca menggunakan proses reduksi berbantuan laser gelombang kontinu (continuous-wave/CW) yang dikombinasikan dengan reduksi kimia menggunakan perak nitrat, asam askorbat, dan natrium sitrat. Dua konfigurasi fabrikasi diteliti dengan membentuk pola larik perak pada substrat kaca bagian bawah dan bagian atas. Substrat yang dihasilkan kemudian digunakan untuk mendeteksi nanopartikel polistirena (PS) berukuran 100 nm sebagai analit model. Optimasi kinerja SERS dilakukan dengan memvariasikan daya laser, waktu paparan, posisi titik fokus, geometri larik, kondisi polarisasi linear dan sirkular, serta penggunaan fitur z-stack untuk mengoptimalkan kedalaman fokus. Hasil penelitian menunjukkan bahwa kondisi fabrikasi sangat memengaruhi morfologi dan keseragaman nanostruktur perak, yang selanjutnya menentukan kemampuan penguatan sinyal SERS. Sinyal Raman tertinggi diperoleh pada daya laser 5,5 mW dengan titik fokus pada radius refleksi laser sebesar 10 μm. Pada kondisi tersebut, terbentuk efek aliran meniskus yang kuat selama proses fabrikasi, sehingga menghasilkan struktur dendritik perak yang rapat dan menyediakan lebih banyak titik panas elektromagnetik. Substrat tersebut berhasil mendeteksi puncak Raman karakteristik PS dengan intensitas sekitar 500 cacahan, yang merupakan intensitas tertinggi dalam penelitian ini. Meskipun metode ini menunjukkan potensi besar untuk menghasilkan substrat SERS yang efektif, reproduktibilitas efek aliran meniskus dan pembentukan nanostruktur masih menjadi tantangan. Penelitian selanjutnya perlu difokuskan pada pengendalian fenomena tersebut untuk meningkatkan konsistensi fabrikasi dan kinerja SERS.
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Surface-enhanced Raman scattering (SERS) is an analytical technique capable of detecting low-concentration analytes through the enhancement of Raman signals by plasmonic nanostructures. In this study, silver nanostructures were fabricated on glass substrates using a continuous-wave (CW) laser-assisted reduction process combined with chemical reduction using silver nitrate, ascorbic acid, and sodium citrate. Two fabrication configurations were investigated by patterning silver arrays on the bottom and upper glass substrates. The resulting substrates were then used to detect 100 nm polystyrene (PS) nanoparticles as a model analyte. SERS performance was optimized by varying the laser power, exposure time, focal point position, array geometry, linear and circular polarization conditions, and the use of the z-stack feature to optimize the focal depth. The results showed that the fabrication conditions strongly influenced the morphology and uniformity of the silver nanostructures, which subsequently determined their SERS enhancement capability. The highest Raman signal was obtained at a laser power of 5.5 mW with the focal point positioned at a laser reflection radius of 10 μm. Under these conditions, a strong meniscus flow effect occurred during fabrication, resulting in the formation of densely packed silver dendritic structures that provided a greater number of electromagnetic hotspots. The fabricated substrate successfully detected the characteristic Raman peak of PS with an intensity of approximately 500 counts, representing the highest signal intensity achieved in this study. Although this method shows considerable potential for producing effective SERS substrates, the reproducibility of the meniscus flow effect and nanostructure formation remains a challenge. Future studies should focus on controlling this phenomenon to improve fabrication consistency and SERS performance.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	hamburan Raman yang diperkuat permukaan (SERS), nanostruktur perak, laser gelombang kontinu, reduksi berbantuan laser, nanopartikel polistirena, efek aliran meniskus, optimasi z-stack. ========================================================================================================================================= Surface-enhanced Raman scattering (SERS), silver nanostructures, continuous-wave laser, laser-assisted reduction, polystyrene nanoparticles, meniscus flow effect, z-stack optimization
Subjects:	T Technology > TD Environmental technology. Sanitary engineering > TD427.P62 Microplastics--Environmental aspects.
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User:	Muhammad Fajri Candra
Date Deposited:	31 Jul 2026 06:29
Last Modified:	31 Jul 2026 06:29
URI:	http://repository.its.ac.id/id/eprint/140732

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