Development of a Low-Cost Portable Gas Sensing System Based on Molecularly Imprinted Quartz Crystal Microbalance Sensor for Detection of Eugenol in Clove Oil

A low-cost portable gas sensing system for the detection of eugenol in clove oil is described in this article. The sensor has been developed on a molecularly imprinted polymer (MIP) modified quartz crystal microbalance (QCM) platform. The system has two parts: 1) MIP-QCM sensor and 2) sensor signal measuring unit, which includes a crystal oscillator (10 MHz), a frequency counter (ATmega328P microcontroller unit), a liquid crystal display (LCD), and a data storage unit. A 10-MHz AT cut quartz crystal was coated with the synthesized solution of the optimum ratio of styrene, methyl methacrylate, and divinylbenzene with eugenol as the template. A crystal oscillator based on a simple complementary metal-oxide-semiconductor inverter and ATmega328 microcontroller were used for data generation and transfer. The portable instrument was used for the detection of eugenol in clove oil samples, which revealed reasonably good repeatability (96.37%), reproducibility (92.92%), and fast response time of about 1 min. The system could detect the concentration of eugenol at ppm level in different real samples. Finally, the response of the proposed system was correlated with the response obtained from gas chromatograph.