An ultrasensitive electrochemical sensor based on cotton carbon fiber composites for the determination of superoxide anion release from cells

A sensor is described for determination of superoxide anion (O2˙−). The electrode consists of nitrogen-doped cotton carbon fiber (NCFs) modified with silver nanoparticles (AgNPs) which have excellent catalytic capability. The resulting sensor, best operated at working potentials around −0.5 V (vs. SCE), can detect O2˙− over an extraordinarily wide range that covers 10 orders of magnitude, and the detection limit is 2.32 ± 0.07 fM. The electrode...