Ferry Chrismiadi Nalle, Akhmad Sabarudin, Aditya Ilham Saputra, Alim Romdhoni, Nike Fitayatul Khusnah, Setyawan Purnomo Sakti
The primary quality of food is often associated with its physical attributes, particularly aroma. Key volatile compounds play a critical role in determining food quality. Coffee as a high-potential commodity in Indonesia and in the world strongly depends on their aroma as a signature for its quality. Several methods have been performed to determine the quality of coffee like cupping methods and chromatography-based technologies. But it depends on the coffee-experts who cannot be replicated by other people because of their subjectivity and still need complex sample processing and lengthy time-analysis. QCM sensor paves the way to solve this problem. By modification of its surface with nanomaterials, QCM sensing performance significantly can be elevated. This study aimed to detect the aroma of roasted coffee using a QCM-based electronic nose sensor. The QCM sensor was coated with aroma-sensitive materials to improve its sensing capabilities, specifically PMMA and PMMA-rGO composites. Both PMMA and PMMA-rGO were synthesized via an in situ polymerization method utilizing a binary solvent system in optimized proportions. The surface roughness of the QCM sensor was slightly higher when coated with PMMA-rGO (Sa = 493.68 ± 74.23 nm) compared to PMMA (Sa = 446.02 ± 26.19 nm) alone. The incorporation of rGO significantly enhanced the sensitivity of the QCM sensor towards the roasted coffee aroma. Based on the Sauerbrey calculation, the value of Δf for PMMA is –66.05 ± 28.77 Hz while for PMMA-rGO is –74.28 ± 36.40 Hz. These findings suggest that PMMA-rGO composites hold considerable promise as effective sensing materials for improving QCM sensor performance. © 2025, Walailak University. All rights reserved.
Department of Chemistry, Brawijaya University, Malang, 65142, Indonesia; Integrated Research Laboratory (LRT-UB), Brawijaya University, Malang, 65142, Indonesia; Department of Physics, Brawijaya University, Malang, 65142, Indonesia; Sensor Technology Laboratory (SenTLab), Department of Physics, Brawijaya University, Malang, 65142, Indonesia
