Specific ultralow level chemo-recognition using Graphene-fluorophore supramolecular assembly: Fine-tuning the fluorophore framework

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 266; p. 120408
• Main Authors: A. K., Akhila, Babu A.R., Suresh, A. Anappara, Aji, N. K., Renuka
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.02.2022
• Subjects: Cu2+ sensor; Non-covalent interaction; Reduced graphene oxide; Sub-zeptomolar detection; Sub-zeptomolar detection; Non-covalent interaction; Reduced graphene oxide; Cu2+ sensor
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2021.120408

[Display omitted] •First report on fine-tuning fluorophore framework to achieve desired selectivity.•First report on moulding fluorophores to achieve molecular level sensitivity.•First report on sub-zeptomole detection of Cu2+ ion.•Excellent Selectivity of the sensor towards Cu2+ ion.•Wide dynamic range of detection of cupric ion.•Sub-zeptomole detection of cupric ion using solid state sensor.•Molecular level logic gate formulation. The non-covalent interactions between graphene and aromatic fluorophores have generated highly sensitive fluorimetric turn-on sensors for various significant analytes. Herein, the supramolecular interaction between reduced graphene oxide and 7-Hydroxy-4-Methyl-8-Amino Coumarin is made use of for tracing Cu2+ at sub-zeptomole level with excellent selectivity among a collection of nineteen metal ions. The system enables quantification of the analyte in a commendably wide range, from micromolar to zeptomolar, a feature that almost all-optical sensors lack. Handy solid-state sensor strip fabricated using the above-mentioned supramolecular combination enabled visual recognition of Cu2+ions at the molecular level. Based on the chemo recognition ability of the fluorophore, multiple Boolean logic devices operating at the molecular level are proposed. By screening pertinent coumarin derivatives, it is demonstrated that the selectivity and sensitivity of the sensors of this sort are decided by the number of π- interaction centers of the fluorophores and the strength by which they interact with graphene, respectively, which will enable identification and modification of proper fluorophores for ultra-trace detection of contaminants of environmental relevance from aqueous solutions.