Employing Conductive Metal–Organic Frameworks for Voltammetric Detection of Neurochemicals

• Published in: Journal of the American Chemical Society 2020-07, Vol.142 (27), p.11717-11733
• Main Authors: Ko, Michael, Mendecki, Lukasz, Eagleton, Aileen M, Durbin, Claudia G, Stolz, Robert M, Meng, Zheng, Mirica, Katherine A
• Format: Article
• Language: English
• Subjects: Ascorbic Acid - analysis; Biosensing Techniques; Dopamine - analysis; Electric Conductivity; Electrochemical Techniques; Electrodes; Metal-Organic Frameworks - chemistry; Particle Size; Serotonin - analysis; Surface Properties; Uric Acid - analysis
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.9b13402

This paper describes the first implementation of an array of two-dimensional (2D) layered conductive metal–organic frameworks (MOFs) as drop-casted film electrodes that facilitate voltammetric detection of redox active neurochemicals in a multianalyte solution. The device configuration comprises a glassy carbon electrode modified with a film of conductive MOF (M3HXTP2; M = Ni, Cu; and X = NH, 2,3,6,7,10,11-hexaimino­triphenylene (HITP) or O, 2,3,6,7,10,11-hexa­hydroxy­triphenylene (HHTP)). The utility of 2D MOFs in voltammetric sensing is measured by the detection of ascorbic acid (AA), dopamine (DA), uric acid (UA), and serotonin (5-HT) in 0.1 M PBS (pH = 7.4). In particular, Ni3HHTP2 MOFs demonstrated nanomolar detection limits of 63 ± 11 nM for DA and 40 ± 17 nM for 5-HT through a wide concentration range (40 nM–200 μM). The applicability in biologically relevant detection was further demonstrated in simulated urine using Ni3HHTP2 MOFs for the detection of 5-HT with a nanomolar detection limit of 63 ± 11 nM for 5-HT through a wide concentration range (63 nM–200 μM) in the presence of a constant background of DA. The implementation of conductive MOFs in voltammetric detection holds promise for further development of highly modular, sensitive, selective, and stable electroanalytical devices.