▎ 摘　　要

As the energy transfer mediator in the metabolism of human beings, dihydronicotinamide adenine dinucleotide (NADH) is considered as an important biomarker, the concentration of which is correlated to several lethal diseases, such as breast cancer and Parkinson's disease. Due to the high oxidation potential encountered for NADH direct oxidation, herein, we report an active electrode for indirect electrochemical detection of NADH at low potential with the inexpensive stainless steel fiber felt (SSFF). The SSFF electrodes were modified through the layer-by-layer assembling of amino-graphene (AG) fragments and Nafion, and characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). Taking the peak current at the apparent oxidation potential (-0.2V) as the sensing signal, the proposed SSFF active electrode presented a stable logarithmic detection range from 100 nM to 300M with R-2=0.996. The regeneration process was also explored and proved to be robust. Finally, the SSFF active electrode was applied to sense NADH in a bio-mixture solution prepared from tumor cell lysate. The experimental results demonstrated that, with a facile processing, the corrosion resistant and low cost SSFF electrodes could serve as a reliable and practical probe for NADH detection, which would further benefit the clinical diagnostics of NADH-related diseases.