Improved sensitivity for the electrochemical biosensor with an adjunct probe.
Despite their promising applications in the biomedical research, the development of electrochemical biosensors with improved sensitivity and low detection limit has remained a great challenge. Here, we demonstrate a new approach to improve the sensitivity of the electrochemical biosensor by simply introducing an adjunct probe into its construction. This signal-on biosensor consists of a thiol-functionalized capture probe attached on the gold electrode surface, an electrochemical sign (methyl blue, MB)-modified reporter probe which is complementary to the capture probe, and an adjunct probe attached nearby the capture probe. The adjunct probe functions as a fixer to immobilize the element of reporter probe which is displaced by the target DNA and protein, increasing the chance of the dissociative reporter probe to collide with the electrode surface and facilitating the electron transfer. The biosensor with an adjunct probe exhibits improved sensitivity and a large dynamic range for DNA and the thrombin assay and can even distinguish 1-base mismatched target DNA. Importantly, the use of this biosensor is not limited to such and is viable for sensitive detection of numerous biomolecules, including RNA, proteins, and small molecules such as cocaine.
Yang
Kun
K
Institute of Biomedical Engineering and Health Technology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
Zhang
Chun-Yang
CY
D000818:Animals; D052157:Aptamers, Nucleotide / Q000378:metabolism; D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D004247:DNA / Q000737:chemistry / Q000235:genetics; D015342:DNA Probes / Q000737:chemistry* / Q000235:genetics; D004563:Electrochemistry; D004566:Electrodes; D004579:Electron Transport; D008751:Methylene Blue / Q000737:chemistry; D009693:Nucleic Acid Hybridization; D013499:Surface Properties; D013917:Thrombin / Q000032:analysis / Q000378:metabolism
D052157:Aptamers, Nucleotide; D015342:DNA Probes; D004247:DNA; D013917:Thrombin; D008751:Methylene Blue