The DNA probe modified with ferrocene and sulfydryl immobilized on the surface of gold electrode through self-assembly method

and ferrocene as electronic medium for construction of electrochemical DNA sensor.The target DNA can be quantitatively detected based on the difference of peak current of DNA sensor before and after hybridization. In addition

by studying on relationship between scanning frequency of square wave voltammetric（ SWV） and transmission rate of ferrocene electronic medium before and after hybridization with target DNA

optimize scanning frequency. The result shows that while the scanning frequency is 200 Hz

concentration of the target DNA in the range of 5

. 0 × 10

-9

～ 1. 0 × 10

-7

mol/L

peak current change and target DNA concentration have a linear relation linear fitting equation ΔI

P

/I

0

（ %） = 0. 76095 + 0. 61065 C

and the detection limit is 1. 7 ×10

-9

mol/L（ S/N = 3）.