Abstract
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 language | English |
|---|---|
| Pages (from-to) | 233-238 |
| Number of pages | 6 |
| Journal | Biosensors and Bioelectronics |
| Volume | 38 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2012 Oct |
Bibliographical note
Funding Information:This work was supported by a grant from the Ministry for Health, Welfare and Family Affairs, Republic of Korea (Grant no. A081023 ), the National Research Foundation (NRF) of Korea grant funded by the Korea government (Ministry of Education, Science and Technology [MEST] , Grant no. 2010-00579-KORANET ), and the Scientific and Technological Research Council of Turkey (TUBITAK) , Project no. 110E287 .
Keywords
- Aptamer
- Capacitive biosensor
- Nampt (PBEF/visfatin)
- SELEX
ASJC Scopus subject areas
- Biotechnology
- Biophysics
- Biomedical Engineering
- Electrochemistry