Rationally designed graphene channels for real-time sodium ion detection for electronic tongue

초록

Monitoring taste-inducing ions and molecules continuously in liquids or solutions is of great considerable matter for the realization of the electronic tongue (E-tongue). Particularly from the five major tastes, the highly selective, sensitive detection of Na+ in real-time is prioritized. Prioritization is due to the saltiness of food is the key ingredient in most meals. Nevertheless, existing Na+ detecting devices have relatively low performances of selectivity, sensitivity, and lack of on-off functions. Additionally, conventional devices significantly deteriorate in capacity due to repetitive usage or lifetime shortage by degradation of the sensing material. Herein, a graphene-based channel was rationally designed by the facile decoration of Calix[4]arene and Nafion to address this issue. They act as a receptor and a molecular sieve, respectively, to enhance selectivity and sensitivity and elongate the life expectancy of the device. This device was merged with a microfluidic channel to control the injection and withdrawal of solutions to fulfill dynamic on-off functions. The fabricated device has highly selective, sensitive Na+ detection properties compared to other 10 molecule/ionic species. Dynamic on-off functions of the device were available, also possesses a long lifespan of at least 220 days. Additionally, it can precisely discriminate real beverages containing Na+, which can be observed by principal component analysis plot. These features offer the possibility of ascending to a platform for E-tongues in near future.

키워드