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Rapid Nanoprobe Signal Enhancement by In Situ Gold Nanoparticle Synthesis
Published on: March 7, 2018
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A highly sensitive nanoscale pH-sensor using Au nanoparticles linked by a multifunctional Raman-active reporter
Latevi S Lawson1, James W Chan, Thomas Huser
1NSF Center for Biophotonics Science and Technology, University of California, Davis, Sacramento, California 95817, USA.
Nanoscale
|June 7, 2014
Summary
A novel single molecule enables controlled nanoparticle aggregation for enhanced Raman scattering (SERS) sensing. This breakthrough creates reproducible pH nanoprobe signals for cellular imaging, improving SERS applications.
Area of Science:
- Nanotechnology
- Chemical sensing
- Spectroscopy
Background:
- Surface-enhanced Raman scattering (SERS) requires controlled nanoparticle aggregation for maximal signal enhancement.
- Current methods using salts or linkers for aggregation suffer from poor reproducibility and inefficient use of SERS hotspots.
- Existing probes often lack spectral consistency between nanoparticle clusters.
Purpose of the Study:
- To develop a single-molecule solution for creating SERS hotspots and sensing pH.
- To engineer a highly reproducible and robust SERS-based pH nanoprobe.
- To demonstrate the utility of the novel nanoprobe in live cellular imaging.
Main Methods:
- Utilized 3,5-dimercaptobenzoic acid as a multifunctional molecule for gold nanosphere aggregation and pH reporting.
- Investigated the SERS signal reproducibility and pH sensitivity of the functionalized nanospheres.
- Applied the developed nanoprobe for imaging pH distribution within human induced pluripotent stem cells (hiPSCs).
Main Results:
- 3,5-dimercaptobenzoic acid effectively induced controlled aggregation, creating stable SERS hotspots.
- The resulting probes exhibited highly reproducible SERS signals across the physiological pH range.
- The nanoprobe demonstrated excellent pH resolution and was successfully used for intracellular pH imaging in hiPSCs.
Conclusions:
- A single molecule, 3,5-dimercaptobenzoic acid, can simultaneously induce SERS hotspot formation and act as a pH reporter.
- This approach significantly improves SERS signal reproducibility and probe efficiency.
- The developed nanoprobe offers a powerful tool for nanoscale pH sensing in biological systems, including cellular environments.
