Related Experiment Video
Updated: Jun 18, 2026
03:38
Aptamer-Based Target Detection Facilitated by a 3-Stage G-Quadruplex Isothermal Exponential Amplification Reaction
Published on: October 6, 2022
Direct optical detection of aptamer conformational changes induced by target molecules
Oara Neumann1, Dongmao Zhang, Felicia Tam
1Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
Analytical Chemistry
|November 26, 2009
Summary
This study introduces a label-free detection method using surface-enhanced Raman spectroscopy (SERS) to identify molecular targets. The technique quantifies aptamer conformational changes, distinguishing specific interactions from nonspecific binding.
Area of Science:
- Biophysical Chemistry
- Analytical Chemistry
- Molecular Biology
Background:
- Aptamers are nucleic acid or peptide molecules that bind specific targets.
- Surface-enhanced Raman spectroscopy (SERS) offers sensitive molecular detection.
- Label-free detection methods are crucial for real-time molecular interaction studies.
Purpose of the Study:
- To develop a label-free method for detecting aptamer-target interactions using SERS.
- To quantify aptamer conformational changes upon target binding.
- To differentiate specific aptamer-target binding from nonspecific interactions.
Main Methods:
- Self-assembled monolayers of thiol-bound DNA aptamers on gold nanoshells.
- Surface-enhanced Raman spectroscopy (SERS) for spectral analysis.
- Spectral cross-correlation function (Gamma) to quantify spectral changes.
Main Results:
- Pristine anti-platelet-derived growth factor (PDGF) aptamer SERS spectra showed high reproducibility (Gamma = 0.91 ± 0.01).
- Incubation with PDGF significantly reduced SERS spectral reproducibility (Gamma = 0.67 ± 0.02), indicating conformational change.
- The SERS approach successfully discriminated cocaine aptamer binding to cocaine from nonspecific analyte interactions.
Conclusions:
- SERS combined with a spectral cross-correlation function provides a robust, label-free method for aptamer-target interaction analysis.
- This technique effectively quantifies aptamer conformational dynamics induced by molecular targets.
- The method demonstrates potential for specific analyte detection in complex biological samples.
