relation: https://eprints.untirta.ac.id/45685/
title: Deteksi Label Magnetik Fe3O4/kitosan Menggunakan Sensor Giant Magnetoresistance Chip dengan Rangkaian Jembatan Wheatstone
creator: AJI PRAYOGA, GALIH
subject: QC Physics
description: This study reports the development of a biosensor based on giant magnetoresistance (GMR) chip as a transducer and Fe3O4/chitosan nanocomposite as a magnetic label. The AAL024 commercial chip that functions as a GMR sensor is combined with an Arduino microcontroller and a differential amplifier to obtain a digital output signal. Fe3O4/chitosan nanocomposites have been successfully obtained through the coprecipitation method with variations in Fe3O4/chitosan concentrations of 4:1 (FK1), 4:2 (FK2), 4:3 (FK3), and 4:4 (FK4). The results of x-ray diffraction analysis showed Fe3O4 has a cubic inverse spinel crystal structure and an increase in crystallite size due to the addition of chitosan, from (8.96 ± 0.13) to (10.24 ± 0.24) nm. Morphological analysis and elemental composition showed that the particles had a nearly spherical shape and became more dispersive after being modified with chitosan. The presence of C element indicates that the formation of Fe3O4/chitosan has been successful. This is reinforced by the fourier transform infra-red spectrum of Fe3O4/kitosan with the interlinking of chitosan molecules on the surface of Fe3O4 nanoparticles. Analysis of magnetic properties using Vibrating Sample Magnetometer showed that there was an increase in coercivity field and a decrease in saturation magnetisation after the addition of chitosan. The saturation magnetisation value of Fe3O4/chitosan is in the range of 76.5 - 34.7 emu/g. The modification of Fe3O4 nanoparticles into Fe3O4/chitosan nanocomposites affects the sensitivity of the sensor. The GMR sensor can obtain a signal within 30 s measurement time with high sensitivity of (4.82 ± 0.1), (4.47 ± 0.2) and (2.57 ± 0.3) mV/(mg/mL) and low limit of detection (LOD) of (0.7) and (3.8) mg/mL for Fe3O4 and FK4. These results demonstrate the high sensitivity of GMR sensors in detecting magnetic labels. Therefore, the GMR chip-based sensor integrated with Fe₃O₄/kitosan nanocomposite has great potential to be developed into a competitive and responsive biosensor system.
date: 2025
type: Thesis
type: NonPeerReviewed
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identifier: https://eprints.untirta.ac.id/45685/1/GALIH%20AJI%20PRAYOGA_2280210058_FULLTEXT.pdf
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identifier: https://eprints.untirta.ac.id/45685/10/GALIH%20AJI%20PRAYOGA_2280210058_CP.pdf
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identifier: https://eprints.untirta.ac.id/45685/3/GALIH%20AJI%20PRAYOGA_2280210058_01.pdf
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identifier: https://eprints.untirta.ac.id/45685/4/GALIH%20AJI%20PRAYOGA_2280210058_02.pdf
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identifier: https://eprints.untirta.ac.id/45685/5/GALIH%20AJI%20PRAYOGA_2280210058_03.pdf
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identifier: https://eprints.untirta.ac.id/45685/6/GALIH%20AJI%20PRAYOGA_2280210058_04.pdf
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identifier: https://eprints.untirta.ac.id/45685/7/GALIH%20AJI%20PRAYOGA_2280210058_05.pdf
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identifier: https://eprints.untirta.ac.id/45685/8/GALIH%20AJI%20PRAYOGA_2280210058_REF.pdf
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identifier: https://eprints.untirta.ac.id/45685/9/GALIH%20AJI%20PRAYOGA_2280210058_LAMP.pdf
identifier:   AJI PRAYOGA, GALIH  (2025) Deteksi Label Magnetik Fe3O4/kitosan Menggunakan Sensor Giant Magnetoresistance Chip dengan Rangkaian Jembatan Wheatstone.  S1 thesis, UNIVERSITAS SULTAN AGENG TIRTAYASA.