| 초록 |
Ultrathin and defect-free graphene (Gr) sheets are prepared by a fluid dynamics-induced shear exfoliation method using graphite. The high hydrophobicity and surface area of Gr make it attractive as a solid-contact ion-to-electron transducer for potentiometric K+ sensors, in which the electrodes are fabricated by the screen-printing process. The electrochemical characterization demonstrates that Gr solid contact results in a high double-layer capacitance, potential stability, and strong resistance against water layer, gases, and lights. The Gr-based K+ sensors show a Nernstian slope of 53.53 mV/log[K+] within a linear concentration range of 10‒1–10‒4 M, a low detection limit of 10‒4.28 M, a fast response time of ~8 s, good repeatability, and excellent long-term stability. Moreover, the Gr-based K+ sensors provide accurate ion concentrations in actual samples of human sweat and sports drinks |
