The interface behavior of hemoglobin at carbon nanotube and the detection for H(2)O(2)

Direct electrochemistry of hemoglobin (Hb) is observed at carbon nanotube (CNT) interface. The adsorbing Hb can transfer electron directly at CNT interface compared with common carbon material. The heterogeneous electron transfer rate constant k of Hb can be calculated as 0.062s(-1), the transfer coefficient alpha is 0.21 and the average surface coverage of Hb on CNT surface is 3.58 x 10(-9) +/- 2.7 x 10(-10)mol/cm(2). It is found that the adsorbing Hb still keeps its catalytic activity to H(2)O(2). This sensor was used to detect H(2)O(2). The apparent Michaelis-Menten constant is calculated as 6.75 x 10(-4)molL(-1).