Rapid and sensitive detection of Nampt (PBEF/visfatin) in human serum using an ssDNA aptamer-based capacitive biosensor

Jee Woong Park, Sreenivasa Saravan Kallempudi, Javed H. Niazi, Yasar Gurbuz, Byung Soo Youn, Man Bock Gu

Research output: Contribution to journalArticlepeer-review

33 Citations (Scopus)


A single-stranded DNA (ssDNA) aptamer was successfully developed to specifically bind to nicotinamide phosphoribosyl transferase (Nampt) through systematic evolution of ligands by exponential enrichment (SELEX) and successfully implemented in a gold-interdigitated (GID) capacitor-based biosensor. Surface plasmon resonance (SPR) analysis of the aptamer revealed high specificity and affinity (Kd=72.52nM). Changes in surface capacitance/charge distribution or dielectric properties in the response of the GID capacitor surface covalently coupled to the aptamers in response to changes in applied AC frequency were measured as a sensing signal based on a specific interaction between the aptamers and Nampt. The limit of detection for Nampt was 1ng/ml with a dynamic serum detection range of up to 50ng/ml; this range includes the clinical requirement for both normal Nampt level, which is 15.8ng/ml, and Nampt level in type 2 diabetes mellitus (T2DM) patients, which is 31.9ng/ml. Additionally, the binding kinetics of aptamer-Nampt interactions on the capacitor surface showed that strong binding occurred with increasing frequency (range, 700MHz-1GHz) and that the dissociation constant of the aptamer under the applied frequency was improved 120-240 times (Kd=0.3-0.6nM) independent on frequency. This assay system is an alternative approach for clinical detection of Nampt with improved specificity and affinity.

Original languageEnglish
Pages (from-to)233-238
Number of pages6
JournalBiosensors and Bioelectronics
Issue number1
Publication statusPublished - 2012 Oct


  • Aptamer
  • Capacitive biosensor
  • Nampt (PBEF/visfatin)

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry


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