Electrochemical logical operations utilizing biological molecules(protein or DNA), which can be used in disease diagnostics and bio-computing, have attracted great research interest. However, the existing logic operations, being realized on macroscopic electrode, are not suitable for implantable logic devices. Here, we demonstrate DNA-based logic gates with electrochemical signal as output combined with gold flower microelectrodes. The designed logic gates are of fast response, enzyme-free, and micrometer scale. They perform well in either pure solution or complex matrices, such as fetal bovine serum,suggesting great potential for in vivo applications. Electrochemical logical operations utilizing biological molecules (protein or DNA), which can be used in disease diagnostics and bio-computing, have attracted great research interest. However, the existing logic operations, being realized on macroscopic electrodes, are not suitable for implantable logic devices Here, we demonstrate DNA-based logic gates with electrochemical signal as output combined with gold flower microelectrodes. The designed logic gates are of fast response, enzyme-free, and micrometer scale. They perform well in either pure solution or complex matrices, such as fetal bovine serum, suggesting great potential for in vivo applications.