title: Label-Free Electrochemiluminescence Aptasensor for 2,4,6-Trinitrotoluene Based on Bilayer Structure of Luminescence Functionalized Graphene Hybrids.
abstract: The electrochemiluminescence (ECL) behavior of N-(aminobutyl)-N-(ethylisoluminol)/hemin dual-functionalized graphene hybrids (A-H-GNs) and luminol-functionalized silver/graphene oxide composite (luminol-AgNPs-GO) was investigated under cyclic voltammetry and pulse potential. It was found that A-H-GNs and luminol-AgNPs-GO exhibited excellent ECL activity. On this basis, a label-free ECL aptasensor for 2,4,6-trinitrotoluene (TNT) detection was developed based on bilayer structure of luminescence functionalized graphene hybrids consisting of A-H-GNs and luminol-AgNPs-GO. First, positively charged chitosan-coated A-H-GNs were modified on the surface of indium-doped tin oxide electrode by simple dripping and drying in the air; after that, the modified electrode was immersed in negatively charged luminol-AgNPs-GO modified with aptamer (apta-biotin-SA-luminol-AgNPs-GO) to form apta-biotin-SA-luminol-AgNPs-GO/CS-A-H-GNs/ITO electrode (i.e., aptasensor) by electrostatic interaction. In the presence of TNT, a remarkable decrease in ECL signals was observed due to the formation of aptamer-TNT complex. TNT could be detected based on the inhibition effect. The aptasensor exhibits a wide dynamic range from 1.0 × 10(-12) to 1.0 × 10(-9) g/mL, with a low detection limit of 6.3 × 10(-13) g/mL for the determination of TNT, which is superior to most previously reported bioassays for TNT. Moreover, the proposed aptasensor has been successfully applied to the detection of TNT in environmental water. It is sensitive, selective, and simple, avoiding complicated labeling and purification procedures. Due to the wide target recognition range of aptamer, this strategy provides a promising way to develop new aptasensor for other analytes.
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, University of Science and Technology of China , Hefei, Anhui 230026, People's Republic of China.|Laboratory for Pollution Monitoring and Control, School of Chemistry and Chemical Engineering, Xinjiang Normal University , Urumqi, Xinjiang 830054, People's Republic of China.
authors.forename: Guixin
authors.initials: G
authors.lastname: Li
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, University of Science and Technology of China , Hefei, Anhui 230026, People's Republic of China.|College of Marine Science, Shandong University at Weihai , Weihai 264209, People's Republic of China.
authors.forename: Xiuxia
authors.initials: X
authors.lastname: Yu
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, University of Science and Technology of China , Hefei, Anhui 230026, People's Republic of China.
authors.forename: Danqing
authors.initials: D
authors.lastname: Liu
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, University of Science and Technology of China , Hefei, Anhui 230026, People's Republic of China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Liu
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, University of Science and Technology of China , Hefei, Anhui 230026, People's Republic of China.
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, University of Science and Technology of China , Hefei, Anhui 230026, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Cui