Signal-amplified electrochemical aptasensor based on multi-branched circular DNA and bimetallic nanomaterials for sensitive histamine detection in complex food matrices.

BACKGROUND

Histamine is a high-risk biogenic amine produced during food spoilage. Excessive intake can trigger severe allergic reactions or poisoning, making the development of an accurate detection method critically important. This study proposes a novel electrochemical aptasensor for the sensitive detection of histamine.

RESULTS

The sensor comprises a multi-branched circular DNA structure, thionine/Au@prussian blue analog (Thi/Au@PBA), Au@Pd nanoflowers (Au@Pd NFs), and an Apt screened via molecular docking and experiment. Compared with the linear DNA, the amplification effect of the circular was observed with low and high concentrations, demonstrating that the circular structure can effectively enhance the sensor's signal. The response signal difference between the presence and absence of the target on the Au@Pd NFs-modified electrode was 1.55 times that of the bare electrode. Furthermore, in a solution of Thi at a certain concentration, the signal response of the Au@PBA-modified electrode was 2.77 times that of the bare electrode. The resulting aptasensor exhibited an ultra-low detection limit of 2.16 pg/mL and a broad linear range (0.01-500 ng/mL) for histamine, alongside high selectivity, reproducibility, repeatability and stability. The sensor's accurate detection results in food matrices (salmon, canned tuna, and red wine) have confirmed its practical value.

SIGNIFICANCE AND NOVELTY: This study proposes an electrochemical aptasensor based on multi-branched circular DNA and bimetallic nanomaterials for the sensitive detection of histamine. This sensor shows great potential in the field of rapid food safety detection.