A nanohybrid based on porphyrin dye functionalized graphene oxide for the application in non-enzymatic electrochemical sensor

Abstract

A zinc porphyrin dye (YD2-o-C8, designated as YD) noncovalently functionalized graphene oxide (GO) nanohybrid (GO@YD) was facilely synthesized through hydrogen bonding and π−π stacking interaction, which was characterized by spectroscopic techniques, electrochemistry, and density functional theory (DFT). The fast electrons transfer from YD to GO and the low binding energy occurred in GO@YD nanohybrid suggest that the nanohybrid possesses remarkable electrochemical properties. However, the inner electroactivity of insoluble YD on GO could be aroused only by combining cationic surfactant of tetraoctylammonium bromide (TOAB). Therefore, the GO@YD nanohybrid encapsulated by TOAB was firstly modified on glassy carbon electrode (GCE) to fabricate the TOAB/GO@YD/GCE, which was then electrochemically reduced to obtain the fabricated sensor (TOAB/ERGO@YD/GCE). The sensor was employed to sense ascorbic acid (AA) and it showed a high sensitivity of 13.58 μA mM−1, a wide linear concentration from 1.33 μM to 1.46 mM (R = 0.998), and a limit of detection (LOD) as low as 0.28 μM. The sensor not only showed high selectivity but also exhibited excellent operational and storage stability due to the hydrophobicity of TOAB. The great potential of the TOAB/ERGO@YD/GCE for practical and reliable AA analysis in the fields of food analysis, clinical tests, and the pharmaceutical industry suggests that the electron mediator of YD combined with the electron accelerator of ERGO and the electron rouser of TOAB possesses special advantages for fabricating non-enzymatic electrochemical sensor.