Greenly synthesized silver nanoparticles for supercapacitor and electrochemical sensing applications in a 3D printed microfluidic platform

Herein, Silver nanoparticles (AgNPs) decorated pencil graphite electrodes (PGEs), with assimilation of Chitosan (CS), as a versatile electrode material for supercapacitor and electrochemical sensing application have been reported. The AgNPs were prepared by employing a green synthesis method using marigold flower s extract. Marigold flower contains lutein, which can be used as a reductant. The morphology and crystal structure of the prepared nanomaterial was characterized by Field emission scanning electron microscopy (FESEM), Elemental Dispersive X-Ray Spectroscopy (EDX), Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), UV-VIS Spectrophotometer and X-ray photoelectron spectroscopy (XPS). The prepared hybrid material, PGE/AgNPs/CS was utilized in an electrochemical 3D printed microfluidic device for supercapacitor and electrochemical sensing of H2O2. As a supercapacitor, the device provided a remarkable storage capacity of 367.16 mF cm−2at a current density of 1 mA cm−2 with high cyclic stability over 1500 charge-discharge cycle. Subsequently, H2O2 sensing with the same electrode in a three-electrode microfluidic system gave a LOD of 0.52 µM within a linear range of 1-10 µM. In addition, the effect of common interfering species, including ascorbic acid (AA), uric acid (UA) dopamine (DA) and xanthine (XN) were thoroughly investigated. Thus, the prepared hybrid electrode material showed excellent electrochemical activity for the supercapacitor and electrochemical sensing of H2O2, which can be further assessed for other relevant applications.