▎ 摘 要
Core-shell CdS@TiO2 nanoparticles were synthesized and characterized by SEM, EDS. The as prepared core-shell nanoparticles and nitrogen doped graphene were utilized to promote the electron transfer of hemoglobin. It is found that the nano-materials can effectively enhance the direct electron transfer of hemoglobin with symmetrical peak separation of 50 mV and formal peak potential of 0.395 V, and it is also found the formal potential shifts with pH in the range of 4.0-9.0 with a slope of 32 mV/pH to reveal a redox Bohr effect in the electron transfer process. The direct electron transfer (DET) of hemoglobin can also be estimated by heterogeneous electron transfer coefficient of 3.60 s(-1). The proposed biosensor shows its favourable reproducibility, stability and low detection limit (5.4x 10(-8) mol/L) for hydrogen peroxide and Michealis-Menten constant of 0.012 mmol/L.