An electrochemical biosensor based on single-stranded DNA modified gold electrode for acrylamide determination

• A simple and effective ssDNA/GE electrochemical biosensor for AA was established.
• ssDNA/GE electrochemical biosensor was used to detect AA in food samples.
• Electrochemical oxidation of AA-ssDNA on the surface of GE was well investigated.

Herein, a simple and effective electrochemical biosensor for sensitive detection of acrylamide (AA) was developed by differential pulse voltammetry (DPV) approach. This biosensor was prepared by effective self-assembling process of thiol group functionalized single-stranded DNA (ssDNA) on the surface of gold electrode (GE) through specific AuS covalent bond. The ssDNA/GE showed a single strong DPV oxidation peak, which was used as the electrochemical signal for AA sensing. The bonding interaction between AA and ssDNA was confirmed by UV–vis absorption spectrometry and DPV. AA and ssDNA formed a single complex and the binding ratio of AA with ssDNA was one AA per guanine base of ssDNA. The electrochemical oxidation of AA-ssDNA adduct on the surface of GE was an adsorption-controlled irreversible reaction and a two-electron two-proton transfer process. Under optimum conditions, ssDNA/GE exhibited excellent DPV response depending on the concentration of AA in 0.4–200 μM range. The limit of detection was 8.1 nM (3 σ/slope). This electrochemical biosensor displayed good reproducibility and high stability. This biosensor was successfully applied to the determination of AA in tap water and potato crisps. This electrochemical platform is convenient and efficient, offering great potential for construction of electrochemical biosensors toward various toxic substances.

An electrochemical biosensor based on single-stranded DNA modified gold electrode for acrylamide determination.Figure optionsDownload as PowerPoint slide