The use of carbon-based nanomaterials conjugated to cobalt phthalocyanine complex in the electrochemical detection of nitrite

This work reports on the non-covalent conjugation of carbon-based nanomaterial with tris(4-tert-butylphenoxy)-(5-phenoxylpicolinic acid) phthalocyanato cobalt (II) (CoPc). The CoPc was pi-stacked onto the graphene quantum dots (GQDs), nitrogen-doped quantum dots (NGQDs) and the single-walled carbon nanotubes (SWCNTs) yielding CoPc@GQDs, CoPc@NGQDs and CoPc@SWCNTs, respectively. The hybrids were charac-terised using various analytical techniques. The CoPc and conjugates were studied electrochemically and used as electrocatalysts in the electrooxidation/detection of nitrite. The sensitivities (3-28 mu A mu M-1), catalytic rate constants (1.8 x 102-5.42 x 104 M-1 s-1) and limits of detection (0.17-1.70 mu M) obtained herein show that the electrocatalysts have good nitrite detection capabilities, comparable to those in literature.

Automated summary

This study presents the non-covalent conjugation of carbon-based nanomaterial with tris(4-tert-butylphenoxy)-(5-phenoxylpicolinic acid) phthalocyanato cobalt (II) (CoPc). The hybrids of CoPc with graphene quantum dots (GQDs), nitrogen-doped quantum dots (NGQDs), and single-walled carbon nanotubes (SWCNTs) were successfully synthesized and characterized. The electrochemical analysis showed that the CoPc and its conjugates exhibited good nitrite detection capabilities, with sensitivities (3-28 mu A mu M-1), catalytic rate constants (1.8 x 102-5.42 x 104 M-1 s-1), and limits of detection (0.17-1.70 mu M) comparable to those in literature.