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Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors
Published on: September 10, 2013
Quantum-dot/dopamine bioconjugates function as redox coupled assemblies for in vitro and intracellular pH sensing
Igor L Medintz1, Michael H Stewart, Scott A Trammell
1Center for Bio/Molecular Science and Engineering Code 6900, US Naval Research Laboratory, Washington, District of Columbia 20375, USA. igor.medintz@nrl.navy.mil
Nature Materials
|July 24, 2010
Summary
Semiconductor quantum dots (QDs) conjugated with dopamine create novel pH sensors. These bioconjugates leverage dopamine
Area of Science:
- Biotechnology
- Nanotechnology
- Analytical Chemistry
Background:
- Semiconductor quantum dots (QDs) are sensitive to charge-transfer processes affecting their optical properties.
- Dopamine exhibits pH-dependent redox properties, including oxidation to quinone at basic pH.
Purpose of the Study:
- To develop QD-dopamine-peptide bioconjugates as charge-transfer coupled pH sensors.
- To investigate the mechanism of pH-dependent photoluminescence quenching in QDs.
Main Methods:
- Synthesis of QD-dopamine-peptide bioconjugates.
- Electrochemical and spectroscopic characterization of QD quenching.
- In vitro testing of pH sensing in cellular environments.
Main Results:
- QD-dopamine bioconjugates function as effective pH sensors.
- Dopamine-derived quinone acts as an electron acceptor, quenching QD photoluminescence.
- Sensors accurately measured cytoplasmic pH changes during induced alkalosis.
Conclusions:
- QD-dopamine conjugates offer a novel platform for sensitive, charge-transfer coupled pH sensing.
- The developed sensors demonstrate potential for real-time monitoring of intracellular pH.
