A Simple and Convenient Aptasensor for Protein Using an Electronic Balance as a Readout

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biosensing Technology

Background:

• Electronic balances are standard laboratory equipment, primarily used for direct weight measurement.
• The application of electronic balances beyond direct weighing is underexplored, particularly in biosensing.
• Protein quantification is crucial in diagnostics and research, requiring sensitive and accurate detection methods.

Purpose of the Study:

• To develop a novel aptasensor for protein quantification utilizing an electronic balance as a readout.
• To demonstrate the feasibility of using an electronic balance for biomolecule quantitation in bioassays.
• To establish a sensitive and accurate method for detecting thrombin.

Main Methods:

• An aptasensor was designed using two thrombin-specific aptamers, one immobilized on magnetic microparticles and the other functionalized with platinum nanoparticles.
• A sandwich complex formed between thrombin and the aptamers, linking magnetic microparticles and platinum nanoparticles.
• Platinum nanoparticles catalyzed hydrogen peroxide decomposition, generating oxygen gas and displacing water, the weight of which was measured by an electronic balance.

Main Results:

• The electronic balance accurately measured the weight of displaced water, correlating directly with thrombin concentration.
• The aptasensor demonstrated a linear response for thrombin quantification in the range of 0 to 100 nM.
• A low detection limit of 2.8 nM for thrombin was achieved.

Conclusions:

• This study reports the first use of an electronic balance as a signal readout for a novel aptasensor in biomolecule quantification.
• The developed method offers a sensitive, accurate, and accessible approach for protein detection.
• This work expands the application scope of common laboratory equipment in advanced bioassays.