C-entrapped Cu nanoparticles-infused polyaniline-modified cellulose nanofibers for the precise monitoring of xanthine in urine samples

Abstract

Xanthine (Xn), as an intermediate of adenine and guanine metabolism to uric acid, is regarded as one the most important markers for the early diagnosis of metabolic diseases such as gout, Lesch–Nyman syndrome, and xanthinuria. Herein, we report the fabrication of a novel carbon-trapped Cu nanoparticle (C@Cu-NP)-integrated polyaniline and cellulose acetate (PCE)-based electrospun nanofiber (C@Cu-NPs/PCE)-based electrode. The designed novel C@Cu-NPsf/PCE electrode was further applied for the detection of Xn in urine and showed excellent electrocatalytic activity due to their improved charge density and electrical conductivity. Smartly selected green PCE nanofibers serve to enhance the binding affinity towards Xn by offering alternate amine and imine groups. Additionally, these PCE nanofibers facilitate the efficient and consistent flow of ions at the electrode interface. To make use of these key features of PCE, it was additionally incorporated with a highly electrocatalytic active C@Cu-NPs, resulting in the development of novel C@Cu-NPs/PCE. Surprisingly, the developed C@Cu-NPs/PCE sensor displayed excellent electrocatalytic efficiency in terms of sensitivity (0.907 μA μM⁻¹ cm⁻²) with a direct response to Xn concentrations (5–180 μM) with an LOD of 0.008 μM. Additionally, the fabricated C@Cu-NPs/PCE showed the selective monitoring of Xn even in the presence of co-existing interferants. Moreover, this sensor was successfully applied for selective Xn monitoring in urine samples, which suggests its reliability.