Fabrication of single Pt@Au nanowire electrodes for monitoring hydrogen peroxide released from living cells

Single platinum covered Au nanowire electrodes (Pt@AuNWEs) were fabricated by a Cu under-potential deposition (UPD)/Pt redox replacement technique using a single Au nanowire as a template, and were characterized by transmission electron microscopy (TEM), electrochemical method and finite-element simulation. Electrochemical experiments showed that a steady-state current could be achieved for common redox species, such as ferrocene (Fc), ferrocenemethanol (FcCH2OH), K3Fe(CN)6 and Ru(NH3)6Cl3. The prepared single Pt@AuNWEs exhibited unusual electrocatalytic activity towards the reduction of H2O2, and were used to fabricate a nanosensor for the detection of H2O2 with good stability and high selectivity. The as-prepared nanosensor was applied to monitor H2O2 released from living cells stimulated by ascorbic acid with a satisfactory performance.