Highly Sensitive and Selective Potassium Ion Detection Based on Graphene Hall Effect Biosensors

Author： Liu Xiangqi Ye Chen Li Xiaoqing Cui Naiyuan Wu Tianzhun Du Shiyu Wei Qiuping Fu Li Yin Jiancheng Lin Cheng-Te

Publisher： MDPI

E-ISSN： 1996-1944|11|3|399-399

ISSN： 1996-1944

Source： Materials, Vol.11, Iss.3, 2018-03, pp. : 399-399

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Abstract

Potassium (K⁺) ion is an important biological substance in the human body and plays a critical role in the maintenance of transmembrane potential and hormone secretion. Several detection techniques, including fluorescent, electrochemical, and electrical methods, have been extensively investigated to selectively recognize K⁺ ions. In this work, a highly sensitive and selective biosensor based on single-layer graphene has been developed for K⁺ ion detection under Van der Pauw measurement configuration. With pre-immobilization of guanine-rich DNA on the graphene surface, the graphene devices exhibit a very low limit of detection (≈1 nM) with a dynamic range of 1 nM–10 μM and excellent K⁺ ion specificity against other alkali cations, such as Na⁺ ions. The origin of K⁺ ion selectivity can be attributed to the fact that the formation of guanine-quadruplexes from guanine-rich DNA has a strong affinity for capturing K⁺ ions. The graphene-based biosensors with improved sensing performance for K⁺ ion recognition can be applied to health monitoring and early disease diagnosis.