A Study on the Detection of α-Pinene in Indian Cumin Using QCM Sensor Coated With Eco-Friendly Biosynthesized Gold Nanomaterial

The development of an eco-friendly Quartz Crystal Microbalance (QCM) sensor for detecting α-Pinene present in Indian cumin has been reported here. Gold nanoparticles (AuNP) were synthesized using rose petal extract (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Rosa damascena</i>) and used to coat the sensor surface. A visible color change from yellow to deep pink confirmed successful nanoparticle formation. The coated sensor, with a frequency shift of 4352 Hz after 15 coating cycles, showed high sensitivity (0.1987 Hz/mg L<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup>) and strong linearity (R<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> = 0.9917) in detecting α-Pinene. It also demonstrated good selectivity (29.77%), stability, reproducibility and repeatability under conditions with a temperature of 24 ± 1°C, standard atmospheric pressure and 61% relative humidity (RH). The sensor’s performance has been validated with real cumin samples, showing a high correlation (R<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> = 0.9868) with GC-MS results. With its simple fabrication, low cost and use of sustainable materials, this sensor offers a practical solution for aroma detection in Indian cumin, especially in quality control.