Abstract: As a kind of secondary metabolites mainly produced by Aspergillus and Penicillium, ochratoxin A (OTA) widely exists in cereals, beans, coffee beans, nuts, wine and beer. Toxicology research shows that OTA can cause specific immune dysfunction, and has strong nephrotoxicity, hepatotoxicity, teratogenic, and carcinogenic effects. In order to ensure food safety and human health, it is necessary to establish a sensitive and selective method to detect OTA in food. The electrochemical aptasensor is a novel analysis method combining electrochemical detection technology and nucleic acid aptamer, and has the advantages of good specificity, simple operation, low cost, fast response, and easy on-site detection. In order to improve the sensitivity of electrochemical detection, one type of electrochemical aptasensors were constructed for OTA detection with the aid of signal amplification technologies, including nanomaterials. In this work, a novel electrochemical aptasensor using gold nanostars (GNSs) and nitrogen-doped porous carbon derived from biomass (NDPC) as dual signal amplification strategy was developed for the sensitive detection of OTA. Due to its multi-branched structure, large specific surface area and good electrical conductivity, GNSs were prepared to improve the immobilization amount of OTA aptamer and accelerate the electron transfer on the electrode surface, which played a key role in recognizing the signal amplification. With a large surface area and good biocompatibility, NDPC derived from biomass wheatmeal was prepared and used for increasing the immobilization of complementary DNA and thionine as the second signal amplification strategy. The characterization results of SEM and TEM demonstrated that GNSs and NDPC were successfully prepared. The experimental conditions such as the concentration of Apt and the concentration of NDPC were studied, and the optimum conditions were as follows:the optimum concentration of Apt was 1.5 μmol/L; the optimum concentration of NDPC was 4 mg/mL.The proposed aptasensor presented a linear range from 0.001 ng/mL to 5.000 ng/mL with the limit of detection of 0.22 pg/mL toward OTA detection, which was ascribed that the advantages of GNSs and NDPC, including the large surface area, good biocompatibility, good electrical conductivity, and the favorable ability of electron transfer. The prepared Th-NDPC-cDNA/Apt-GNSs/NH₂-AuE sensor was used to detect OTA content in corn sample, and the average recovery rate was 89%-104%, indicating that the prepared sensor was suitable to detect OTA in actual sample. In summary, we have successfully designed a novel signal-off electrochemical aptasensor based on GNSs and NDPC as double signal amplification for the highly sensitive and effective detection of OTA, which can be expanded to other targets based on aptamers, as well as provides a technological support for food safety.