Judul: Sintesis Carbon Dots (Cds) Dari Rumput Gajah (Pennisetum Purpureum) Dan Aplikasinya Sebagai Sensor Ion Besi(III) ===Synthesis Of Carbon Dots (Cds) From Elephant Grass (Pennisetum Purpureum) And Their Application As An Iron(III) Ion Sensor
Pengarang: Indriana Kartini ; Roto ; Chotimah ; Fathah Dian Sari
Penerbit: FMIPA UGM
Tahun: 2024
Tipe: Disertasi
Lokasi: Perpustakaan Fakultas MIPA
ABSTRAK
Sensor berbasis nanomaterial berfluoresensi saat ini banyak dikembangkan karena mampu mendeteksi keberadaan ion logam dengan cepat dan akurat melalui teknik sederhana berbasis fluoresensi. Material aktif sensor berfluoresensi yang banyak dikembangkan saat ini masih melibatkan ion-ion logam berat yang keberadaan residunya menimbulkan dampak negatif terhadap lingkungan, seperti Cadmium selenida (CdSe) dan Indium galium arsenida (InGaAs), sehingga diperlukan suatu material baru berbasis bahan alam yang lebih ramah lingkungan. Pada penelitian ini diusulkan penggunaan material Carbon Dots (CDs), material baru dalam kelas karbon nanomaterial berdimensi 0 (0D) dengan sifat optik yang khas, yang disintesis dari rumput gajah (Pennisetum purpureum). Tujuan penelitian ini adalah memperoleh CDs yang optimum untuk sensor ion logam dan meningkatkan kinerjanya melalui pasivasi permukaan berupa doping heteroatom. Sintesis dilakukan dengan menggunakan metode hidrotermal satu tahap dengan pelarut akuabides. Karakterisasi sifat optik dilakukan dengan UV-Vis dan spektrofluorometer, analisis gugus fungsi dan senyawa karbon dilakukan dengan spektrofotometer ATR/FTIR dan Raman, sedangkan kristalinitas, ukuran, dan morfologi CDs yang terbentuk dianalisis dengan XRD dan TEM/HRTEM. Penelitian ini dilakukan dalam beberapa tahap yang meliputi optimalisasi sintesis CDs dari rumput gajah dengan variasi berat prekursor, suhu, dan waktu hidrotermal, tahap berikutnya adalah pasivasi melalui doping atom nitrogen dan nitrogen-sulfur, dan tahap terakhir adalah pengujian CDs hasil sintesis sebagai sensor ion logam.
Hasil penelitian menunjukkan bahwa kondisi reaksi optimum sintesis CDs adalah pada suhu 180 °C selama 6 jam dengan berat prekursor 1 g. Carbon dots hasil sintesis memiliki ukuran diameter rata-rata 3,1 nm dan diketahui mengandung gugus-gugus fungsi oksigen (OCG) yang mampu memancarkan emisi fluoresensi pada rentang yang luas antara 350–570 nm dengan quantum yield (QY) sekitar 10,29%. Pemberian doping atom nitrogen dari urea dan etilendiamin (EDA) serta ko-doping atom nitrogen-sulfur dari tiourea terbukti meningkatkan karakteristik fluoresensi CDs yang ditunjukkan dengan adanya peningkatan QY sebesar 28%, 26%, dan 17% berturut-turut untuk N-CDs Urea, N-CDs EDA, dan N,S-CDs. Carbon dots hasil sintesis menunjukkan performa selektivitas dalam mendeteksi ion Fe3+ dalam kisaran konsentrasi 0–600 μM dengan limit deteksi (LOD) sebesar 7,32 μM untuk CDs murni dan 0,023; 0,069; dan 33,37 μM berturut-turut untuk N-CDs Urea, N-CDs EDA, dan N,S-CDs. Dari penelitian ini diketahui bahwa CDs dari rumput gajah sangat potensial untuk diaplikasikan sebagai sensor ion Fe3+ yang selektif dan sensitif melalui mekanisme quenching.===Sensors based on fluorescent nanomaterials are currently in development because they can rapidly and accurately detect the presence of metal ions through simple fluorescence-based techniques. The active fluorescent sensor materials currently under development still incorporate heavy metal ions, such as Cadmium selenide (CdSe) and InGaAs (Indium gallium arsenide), whose residual presence negatively affects the environment. Therefore, there is a need for a new material based on natural ingredients that is environmentally friendly. In this research, Carbon Dots (CDs), a novel class of zero-dimensional (0D) carbon nanomaterials with unique optical properties, synthesized from elephant grass (Pennisetum purpureum), are proposed for use. The objective of this research is to obtain the optimal CDs for metal ion sensors and enhance their performance through surface passivation using heteroatom doping. Synthesis was conducted using a one-step hydrothermal method with deionized water as the solvent. Characterization of optical properties was performed using UV-Vis and a spectrofluorometer, while analysis of functional groups and carbon compounds was carried out using ATR/FTIR and a Raman spectrophotometer. Additionally, the crystallinity, size, and morphology of the formed CDs were analyzed using XRD and TEM/HRTEM.
The research results indicate that the optimal conditions for synthesizing CDs are at a temperature of 180 °C for 6 hours using a precursor weight of 1 g. The synthesized CDs have an average diameter of 3.1 nm and are known to contain oxygen functional groups (OCG), which can emit fluorescence over a wide range from 350–570 nm with a quantum yield (QY) of approximately 10.29%. The introduction of nitrogen atoms from urea and ethylenediamine (EDA), as well as co-doping with nitrogen-sulfur atoms from thiourea, has been proven to enhance the fluorescence characteristics of the CDs, resulting in QY increases of 28%, 26%, and 17% for N-CDs Urea, N-CDs EDA, and N,S-CDs, respectively. Furthermore, the synthesized CDs have demonstrated high selectivity in detecting Fe3+ ions within a concentration range of 0–600 μM, with a limit of detection (LOD) of 7.32 μM for undoped CDs, and 0.023, 0.069, and 33.37 μM, respectively, for N-CDs Urea, N-CDs EDA, and N,S-CDs. This research reveals that CDs derived from elephant grass have the potential to be applied as selective and sensitive Fe3+ ion sensors through a quenching mechanism
ABSTRACT
Sensors based on fluorescent nanomaterials are currently in development because they can rapidly and accurately detect the presence of metal ions through simple fluorescence-based techniques. The active fluorescent sensor materials currently under development still incorporate heavy metal ions, such as Cadmium selenide (CdSe) and InGaAs (Indium gallium arsenide), whose residual presence negatively affects the environment. Therefore, there is a need for a new material based on natural ingredients that is environmentally friendly. In this research, Carbon Dots (CDs), a novel class of zero-dimensional (0D) carbon nanomaterials with unique optical properties, synthesized from elephant grass (Pennisetum purpureum), are proposed for use. The objective of this research is to obtain the optimal CDs for metal ion sensors and enhance their performance through surface passivation using heteroatom doping. Synthesis was conducted using a one-step hydrothermal method with deionized water as the solvent. Characterization of optical properties was performed using UV-Vis and a spectrofluorometer, while analysis of functional groups and carbon compounds was carried out using ATR/FTIR and a Raman spectrophotometer. Additionally, the crystallinity, size, and morphology of the formed CDs were analyzed using XRD and TEM/HRTEM.
The research results indicate that the optimal conditions for synthesizing CDs are at a temperature of 180 °C for 6 hours using a precursor weight of 1 g. The synthesized CDs have an average diameter of 3.1 nm and are known to contain oxygen functional groups (OCG), which can emit fluorescence over a wide range from 350–570 nm with a quantum yield (QY) of approximately 10.29%. The introduction of nitrogen atoms from urea and ethylenediamine (EDA), as well as co-doping with nitrogen-sulfur atoms from thiourea, has been proven to enhance the fluorescence characteristics of the CDs, resulting in QY increases of 28%, 26%, and 17% for N-CDs Urea, N-CDs EDA, and N,S-CDs, respectively. Furthermore, the synthesized CDs have demonstrated high selectivity in detecting Fe3+ ions within a concentration range of 0–600 μM, with a limit of detection (LOD) of 7.32 μM for undoped CDs, and 0.023, 0.069, and 33.37 μM, respectively, for N-CDs Urea, N-CDs EDA, and N,S-CDs. This research reveals that CDs derived from elephant grass have the potential to be applied as selective and sensitive Fe3+ ion sensors through a quenching mechanism
Subyek/Kata Kunci: Carbon dots; doping atom; fluoresensi; rumput gajah; sensor ion logam
