Athi' Nur Auliati Rahmah
Universitas Negeri Yogyakarta

Published : 2 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 2 Documents
Search

Simple Investigation on the Optical Properties of Carbon Nanodots Using Lasers and a Lux Meter Febriani Febriani; Athi' Nur Auliati Rahmah; Bian Itsna Ashfa Al Ashfiya; Juli Astono; Wipsar Sunu Brams Dwandaru
Jurnal Fisika dan Aplikasinya Vol 18, No 1 (2022)
Publisher : Lembaga Penelitian dan Pengabdian Kepada Masyarakat, LPPM-ITS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j24604682.v18i1.11005

Abstract

Carbon nanodots (Cdots) have excellent optical properties. This study aims to investigate scattering and absorption of Cdots via simple exposure of ultraviolet (UV)/violet, red, and green lasers. The experiment was conducted by preparing the Cdots from cajuput oil distillation wastes as the precursor. The solid wastes were dried under the sun, grounded into powder, filtered, and carbonized inside an oven at 250 oC for one hour. The carbonized powder was then mixed with distilled water, left for a night, and then filtered again so that the Cdots solution was obtained. Here, the mass of the precursor was varied. The Cdots samples were characterized using ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectroscopies, and also particle size analyzer (PSA). The lasers were directly exposed to the Cdots samples. A digital lux-meter was used to measure the intensity of the lasers transmitted from the sample. The angle of the lux-meter was varied on a circular track. The sample was on the center of the track. The UV-Vis characterization showed two peaks at 217 nm and 270 nm, and a tail extending to the visible region. The PL characterization showed an intensity peak at 509.57 nm, which confirms the cyan luminescence of the Cdots. The PSA characterization indicated that the size of the Cdots was 1.04 nm. Moreover, at an angle of 0o, the UV wavelength was strongly absorbed by the Cdots in accordance with the UV-Vis characterization result. The intensity of the green laser also dominates as it was less absorbed and strongly scattered by the Cdots.
Nanomaterial Carbon-Dots Berbahan Dasar Daun Sirih (Piper Betle L.) Sebagai Antibakteri Terhadap Bakteri S. Mutans dan E. Coli Emi Kurnia Sari; Danvi Sekartaji; Athi' Nur Auliati Rahmah; Wipsar Sunu Brams Dwandaru
POSITRON Vol 10, No 2 (2020): Vol. 10 No. 2 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (627.975 KB) | DOI: 10.26418/positron.v10i2.41731

Abstract

Penelitian ini bertujuan untuk mensintesis, mengkarakterisasi, dan mengetahui peran nanomaterial carbon-dots (Cdots) sebagai antibakteri terhadap bakteri S. mutans dan E. coli. Cdots dibuat dengan bahan dasar daun sirih (Piper Betle L.) menggunakan metode pemanasan oven. Terdapat tiga buah sampel Cdots yang dihasilkan yaitu 0,5 g serbuk daun sirih+aquades (Cdots A), 0,5 g serbuk daun sirih+ekstrak daun sirih (Cdots B), dan 1 g serbuk daun sirih+ekstrak daun sirih (Cdots C). Ketiga sampel memiliki karakteristik yang hampir sama, yaitu adanya puncak absorbansi pada rentang panjang gelombang 257nm – 320 nm. Daya serap yang tinggi pada rentang ultraviolet (UV) merupakan salah satu sifat yang dimiliki Cdots. Selain itu, ketiga sampel Cdots memiliki pendaran biru-kehijauan (cyan) ketika dikenai laser UV.Hal ini merupakan sifat luminesensCdots yang dapat berpendar pada panjang gelombang cahaya tampak. Cdots tersusun dari core dan surface state yang masing-masing ditunjukkan dengan adanya gugus fungsi C=C dan gugus O-H serta C-O yang terdeteksi oleh uji FTIR dari ketiga sampel Cdots. Pengujian antibakteri menggunakan metode Kirby-Bauer menunjukkan sampel Cdots C memiliki aktivitas antibakteri tertinggi karena memiliki konsentrasi Cdots yang lebih banyak dan bekerja sama dengan ekstrak sirih yang memiliki sifat antibakteri sehingga berpotensi sebagai agen antibakteri dibandingkanekstrak daun sirih murni.