Heterojunctions Derived by Integrating Arylene-Ethynylene Nanobelts and N-Doped Graphene for Molecular Sensing

Juanjuan Gao ^{†, ‡}, Yuliang Shen ^‡, Jingkun Fang ^‡, Weiqing Zhu ^‡, Xuezhen Lin ^‡, Haiou Song ^{*, §}, Shupeng Zhang ^{*, †, ‡, ‖}, Xin Wang ^{*, †, ‡}

ABSTRACT

Self-assembled crystalline nanobelts were fabricated from the organically synthesized 4,4'-(((anthracene-9,10-diylbis(ethyne-2,1-diyl))bis(2,5-bis(3,7-dimethyloctyl)-4,1-phenylene))bis(ethyne-2,1-diyl))bis(N,N-diphenylaniline) molecule (AE) by utilizing typical Sonogashira coupling reactions. One dimensional AE with high carrier transportability could be directly integrated with two dimensional N-doped graphene (NG), and the electrocatalytic performance was significantly affected by the rational coupling sensing platform (AE-NG). Further combination of beta-cyclodextrins (CD) with AE-NG could promote the electrochemical signal enhancement of ternary nanocomposites (CD-AE-NG) because of synergetic effects of improved solubility, host-guest recognition, anisotropic charge carrier mobility, conductivity, and electrocatalytic activity. The electrochemical sensor based on CD-AE-NG heterostructure exhibited good electrochemical responses to catechol (CT), aminophenols, p-phenylenediamine, acetaminophen, tryptophan and tyrosine. CD-AE-NG modified electrode (CD-AE-NG/GCE), a representative example for detecting CT, achieved a broader linear range (0.05 - 400 μM) and lower detection limit of 0.026 μM (S/N = 3). Interestingly, the excellent simultaneous detection of APAP and Tyr could be obtained in the simulated body fluid. A detection limit of 0.120 and 0.322 μM (S/N = 3) was obtained for APAP and Tyr, respectively. The positive results show that hierarchical integration of nanobelts and NG has considerable potential in the fabrication of high-performance electrochemical devices.