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Aptamer Conformational Change Enables Serotonin Biosensing with Nanopipettes
Nako Nakatsuka1, Alix Faillétaz1, Dominic Eggemann1
1Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich CH-8092, Switzerland.
Analytical Chemistry
|February 17, 2021
Summary
We developed aptamer-functionalized nanopipettes for highly specific serotonin detection. This novel nanotool enables sensitive, label-free sensing of serotonin in complex biological samples.
Area of Science:
- Nanotechnology
- Biomedical Engineering
- Analytical Chemistry
Background:
- Accurate detection of neurotransmitters like serotonin is crucial for understanding neurological functions.
- Existing sensing methods often face challenges with specificity, sensitivity, and complex sample matrices.
- Aptamer-based sensors offer high specificity but require integration into robust detection platforms.
Purpose of the Study:
- To develop and validate a novel nanopipette-based sensor for the specific and sensitive detection of serotonin.
- To investigate the sensing mechanism using complementary analytical techniques and theoretical modeling.
- To demonstrate the applicability of the sensor in complex biological environments.
Main Methods:
- Fabrication of quartz nanopipettes with ~10 nm orifices.
- Functionalization of nanopipettes with serotonin-specific aptamers.
- Detection of serotonin via changes in ion flux and surface charge.
- Utilized quartz crystal microbalance with dissipation monitoring (QCM-D) and electrochemical impedance spectroscopy (EIS).
- Developed a theoretical model for aptamer-modified nanopipette systems.
Main Results:
- Achieved high specificity and selectivity for serotonin detection.
- Demonstrated picomolar detection limits in neurobasal media, a complex in vitro neuronal culture environment.
- Confirmed aptamer conformational changes and surface charge variations upon serotonin binding.
- Experimental findings were supported by the developed theoretical model.
- Validated the sensor's performance in complex biological matrices.
Conclusions:
- Aptamer-modified nanopipettes represent a promising platform for label-free, rapid serotonin detection.
- The developed nanotool is translatable for sensing small molecules in diverse biological systems.
- This approach offers high sensitivity and specificity, overcoming limitations of current methods.
- Mechanistic insights were gained through complementary techniques and theoretical modeling.
