Immobilization of gold nanoparticles on electrospun polyacrylonitrile/carbon nanotube nanofiber for self-powered electrochemical biosensing of myoglobin

Polyacrylonitrile-carbon nanotube (PAN-CNT) nanofibers were prepared on indium tin oxide (ITO) electrode using electrospinning technique, and gold nanoparticles (AuNPs) were subsequently modified on ITO-PAN-CNT electrode by electrostatic adsorption to construct ITO-PAN-CNT–COOH–AuNPs substrate electrode. The self-powered biosensor consists of a PAN-CNT–COOH–AuNPs-aptamer functionalized biocathode and a PAN-CNT–COOH–AuNPs-glucose oxidase (GO_x) bioanode. By capturing the change in electrode spatial potential resistance before and after myoglobin (Mb), This interaction affects the transmission of electrons between the redox probe [Fe(CN)₆]^3- an d the biocathode, establishing a linear relationship between E^OCV and Mb concentration. The self-powered biosensor displayed a highly sensitive response to the target Mb over a concentration range from 5 to 5 × 10³ ng mL⁻¹, with a limit of detection reaching less than 0.23 ng mL⁻¹ (S/N = 3), and exhibited outstanding stability and selectivity.