Synergetic Effect of Three-in-One Nanocomposite Based on AuNPs and rGO-MWCNTs for Ultrasensitive Electrochemical Bio-Diagnostic Applications

A simple, two-step AuNPs/rGO-MWCNTs nanocomposite fabrication methodology, via drop-casting of rGO-MWCNTs on bare screen printed electrode (SPE) followed by electrodeposition of AuNPs through voltammetric scanning, without using any toxic reducing agents is reported. Each step of the synthesized nanocomposite is characterized using state-of-art spectroscopic and electrochemical methods. Our results demonstrate that the nanostructured AuNPs/rGO-MWCNTs/SPE showed synergistic effects of high electrocatalytic and electron transfer activity, high surface area to volume ratio, that confirms our synthesized material is the best material to fabricate a portable device for rapid, inexpensive, and sensitive electrochemical biosensors. For validation, the fabricated material subjected to electrochemical sensing of BSA protein. Our AuNPs/rGO-MWCNTs nanocomposite exhibited significant and good linear response over 2.5–12.5 μ g ml −1 BSA concentration range, with sensitivity of 1.723 μ A μ g ml −1 and limit of detection (LOD) 0.23 μ g/ml. This portable sensing system with enhanced performance demonstrates great potential for our synthesized AuNPs/rGO-MWCNs/SPE nanocomposite in application of point of care applications, and offers a universal and reliable platform for in biomarker detection.