title: DNA Generated Electric Current Biosensor.
abstract: In addition to its primary function as a genetic material, deoxyribonucleic acid (DNA) is also a potential biologic energy source for molecular electronics. For the first time, we demonstrate that DNA can generate a redox electric current. As an example of this new functionality, DNA generated redox current was used for electrochemical detection of human epidermal growth factor receptor 2 (HER2), a clinically important breast cancer biomarker. To induce redox current, the phosphate of the single stranded DNA aptamer backbone was reacted with molybdate to form redox molybdophosphate precipitate and generate an electrochemical current of ∼16.8 μA/μM cm2. This detection of HER2 was performed using a sandwich detection assay. A HER2 specific peptide was immobilized onto a gold electrode surface for capturing HER2 in buffer and serum. The HER2 specific aptamer was used as both ligand to bind the captured HER2 and to generate a redox current signal. When tested for HER2 detection, the electrochemical current generated by the aptasensor was proportional to HER2 concentration in the range of 0.01 to 5 ng/mL, with a current generated in the range of ∼6.37 to 31.8 μA/cm2in both buffer and serum. This detection level is within the clinically relevant range of HER2 concentrations. This method of electrochemical signal amplification greatly simplifies the signal transduction of aptasensors, broadening their use for HER2 analysis. This novel approach of using the same aptamer as biosensor ligand and as transducer can be universally extended to other aptasensors for a wide array of biodetection applications. Moreover, electric currents generated by DNA or other nucleic acids can be used in molecular electronics or implanted devices for both power generation and measurement of output.
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha, China , 410083.
authors.forename: Lanshuang
authors.initials: L
authors.lastname: Hu
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha, China , 410083.
authors.forename: Shengqiang
authors.initials: S
authors.lastname: Hu
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha, China , 410083.
authors.forename: Linyan
authors.initials: L
authors.lastname: Guo
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha, China , 410083.
authors.forename: Congcong
authors.initials: C
authors.lastname: Shen
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha, China , 410083.
authors.forename: Minghui
authors.initials: M
authors.lastname: Yang
authors.affiliation: National Cancer Institute, National Institutes of Health , Rockville, Maryland 20850, United States.
authors.forename: Avraham
authors.identifier: 0000-0002-7445-9995
authors.initials: A
authors.lastname: Rasooly
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D014408:Biomarkers, Tumor / Q000032:analysis / Q000097:blood; D015374:Biosensing Techniques / Q000379:methods*; D001943:Breast Neoplasms / Q000175:diagnosis / Q000378:metabolism; D055664:Electrochemical Techniques; D004566:Electrodes; D005260:Female; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D010084:Oxidation-Reduction; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis* / Q000097:blood / Q000378:metabolism; D015203:Reproducibility of Results
chemical_list: D052157:Aptamers, Nucleotide; D014408:Biomarkers, Tumor; D006046:Gold; D010455:Peptides; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human