Highly-sensitive voltammetric detection of trinitrotoluene on reduced graphene oxide/carbon nanotube nanocomposite sensor

• Published in: Analytica chimica acta 2018-12, Vol.1035, p.14-21
• Main Authors: Castro, Sílvia V.F., Silva, Murilo N.T., Tormin, Thiago F., Santana, Mário H.P., Nossol, Edson, Richter, Eduardo M., Munoz, Rodrigo A.A.
• Format: Article
• Language: English
• Subjects: 2,4,6-Trinitrotoluene; Analytical chemistry; Boron; Carbon; Chemical sensors; Cyclohexane; Diamond films; Diamonds; Electrochemical impedance spectroscopy; Electrochemistry; Electron transfer; Explosive; Explosives; Explosives detection; Forensics; Graphene; Interfacial method; Multi wall carbon nanotubes; Nanocomposites; Nanomaterials; Nanotechnology; Residues; Security; Sensors; Spectroscopy; Thin films; TNT; Trinitrotoluene
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2018.06.055

This work presents the highly-sensitive detection of 2,4,6-trinitrotoluene (TNT) on reduced graphene oxide/multi-walled carbon nanotube (rGO/MWCNT) nanocomposite sensor. The formation of a thin film of this nanocomposite occurred at the cyclohexane/water immiscible interface of a mixture of MWCNT and rGO in the biphasic solution. The film was transferred to a boron-doped diamond (BDD) electrode for the square-wave voltammetric detection of TNT, which presented improved analytical characteristics in comparison with bare BDD and after modification with precursors. Electrochemical impedance spectroscopy also revealed the faster electron transfer for a redox probe on the nanocomposite modified surface. The synergistic properties of both carbon nanomaterials in the thin film modified surface resulted in a TNT sensor with a detection limit of 0.019 μmol L−1 within a wide linear range (0.5–1100 μmol L−1), with superior performance in comparison with other electrochemical sensors produced with carbon nanomaterials. This new material provides great promises for the highly-sensitive detection of other nitroaromatic explosives as well as other analytes. Moreover, the interfacial method enables the production of homogeneous and stable films on large coated areas as well as the large-scale production of electrochemical sensors. [Display omitted] •Highly-sensitive detection of TNT on rGO/MWCNT nanocomposite sensor.•Thin film of rGO/MWCNT formed at the immiscible interface of a biphasic solution.•Film transferred to a boron-doped diamond (BDD) electrode for TNT detection.•Electrochemical impedance spectroscopy showed faster electron transfer on rGO/MWCNT.•Field submicromolar detection of TNT, promising for forensic police intelligence.