Non-enzymatic electrochemical biosensor based on Pt NPs/RGO-CS-Fc nano-hybrids for the detection of hydrogen peroxide in living cells

• A highly sensitive non-enzymatic electrochemical biosensor was developed.
• This biosensor was constructed based on Pt NPs/RGO-CS-Fc nano-hybrids.
• A synergistic effect was yielded with the integration of Pt NPs, RGO and Fc.
• This biosensor exhibited excellent anti-interference capability and reproducibility.
• The H2O2 in living cells was successfully detected by this biosensor.

A highly sensitive non-enzymatic electrochemical sensor based on platinum nanoparticles/reduced graphene oxide-chitosan-ferrocene carboxylic acid nano-hybrids (Pt NPs/RGO-CS-Fc biosensor) was developed for the measurement of hydrogen peroxide (H2O2). The RGO-CS-Fc nano-hybrids was prepared and characterized by UV–vis spectrum, Fourier transform infrared spectroscopy, transmission electron microscopy, Raman spectrometer and electrochemical impedance spectroscopy. Under optimal experimental conditions, the Pt NPs/RGO-CS-Fc biosensor showed outstanding catalytic activity toward H2O2 reduction. The current response of the biosensor presented a linear relationship with H2O2 concentration from 2.0×10−8 M to 3.0×10−6 M with a correlation coefficient of R2=0.9968 and with logarithm of H2O2 concentration from 6.0×10−6 M to 1.0×10−2 M with a correlation coefficient of R2=0.9887, the low detection limit of 20 nM was obtained at the signal/noise (S/N) ratio of 3. Moreover, the Pt NPs/RGO-CS-Fc biosensor exhibited excellent anti-interference capability and reproducibility for the detection of H2O2. The biosensor was also successfully applied for the detection of H2O2 from living cells containing normal and cancer cells. All these results prove that the Pt NPs/RGO-CS-Fc biosensor has the potential application in clinical diagnostics to evaluate oxidative stress of different living cells.