Protein quantification using resonance energy transfer between donor nanoparticles and acceptor quantum dots

Area of Science:

• Biochemistry
• Nanotechnology
• Analytical Chemistry

Background:

• Protein quantification is crucial in biological research.
• Existing methods may lack sensitivity or require complex procedures.
• Luminescence resonance energy transfer (LRET) offers a sensitive detection mechanism.

Purpose of the Study:

• To develop a homogeneous time-resolved LRET (TR-LRET) assay for protein quantification.
• To utilize luminescent nanoparticles as donors and acceptors for LRET.
• To establish a sensitive and reliable method for quantifying proteins like bovine serum albumin (BSA).

Main Methods:

• Developed a competitive TR-LRET assay using Eu(3+)-loaded nanoparticles (EuNPs) as donors and protein-coated quantum dots (QDs) as acceptors.
• Investigated RET between EuNPs and QD655 or QD705 in the presence and absence of analyte protein (BSA).
• Confirmed and characterized RET using steady-state and time-resolved luminescence spectroscopy.

Main Results:

• Demonstrated RET from EuNPs to QDs, with signal decreasing upon analyte protein presence.
• Determined an average donor-acceptor distance of approximately 15 nm at observed RET efficiencies.
• Achieved limits of detection below 10 ng of BSA with high precision (CV < 10%).

Conclusions:

• The developed TR-LRET assay provides highly sensitive protein quantification.
• The assay exhibits improved sensitivity compared to existing commercial methods.
• The mix-and-measure format has potential for routine protein quantification in biological laboratories.