Direct application of gold nanoparticles to one-pot electrochemical biosensors

• A novel one-pot colloidal AuNPs-based electrochemical biosensor was fabricated.
• AuNPs were first adopted directly as the electrolyte.
• Sensitive detection of glucose and single-nucleotide polymorphism was achieved.
• Without need to modify the electrode, this system can be regenerated easily.

Gold nanoparticles (AuNPs) have been widely employed for the fabrication of electrochemical biosensors. In most cases, AuNPs are immobilized on the surface of an electrode, so they are difficult to be regenerated, making the use of the biosensor unfriendly. In this work, by adopting AuNPs directly as the electrolytes, we have developed a novel AuNPs-based electrochemical detection system. In brief, AuNPs-catalyzed oxidation of glucose is combined with a HRP-catalyzed reaction as well as an electrocatalytic reaction to compose cascade reactions in the electrolyte. Thus, the intensity of the electrocatalytic signals has quantitative relation with the concentration of glucose, and favors the sensitive detection of glucose. Furthermore, because the catalysis of AuNPs may be blocked under the interaction with single-stranded DNA and unblocked in the presence of a complementary sequence, detection of DNA and even single-nucleotide polymorphism can thereby been achieved. This one-pot detection system can be operated and regenerated very easily, since all the components are integrated in the electrolytes of AuNPs, and the unmodified electrode can be reused after being rinsed. This concept by integrating the advantages of sensitive electrochemical detection with the easy-to-operate nanocolloidal system may also promote the development of other kinds of electrochemical biosensors.

Gold nanoparticles (AuNPs) have been widely employed for the fabrication of electrochemical biosensors; AuNPs are usually immobilized on the surface of an electrode, so they are difficult to be regenerated, making use of the unfriendly biosensor. In this work, by adopting AuNPs directly as the electrolytes, we have developed a novel AuNPs-based electrochemical detection system. Moreover, the catalytic property of AuNPs is allowed to be associated with the electrochemical reaction to realize cascade reactions. To demonstrate the principle of this design, sensitive detection of glucose as well as single-nucleotide polymorphism has thereby been achieved. This one-pot detection system can be operated and regenerated very easily, since all the components are integrated in the electrolytes of AuNPs, and the unmodified electrode can be reused after being rinsed. This concept by integrating the advantages of sensitive electrochemical detection with the easy-to-operate nanocolloidal system may also promote the development of other kinds of electrochemical biosensors.Figure optionsDownload as PowerPoint slide