Trace Biomolecule Detection with Functionalized Janus Particles by Rotational Diffusion.

Area of Science:

• Biotechnology
• Nanotechnology
• Immunology

Background:

• Cytokines, like tumor necrosis factor-alpha, are crucial immune signaling molecules.
• Abnormal cytokine levels indicate disease or infection, necessitating early detection.
• Current detection methods may lack the sensitivity for early-stage disease diagnosis.

Purpose of the Study:

• To explore the use of Janus particles and rotational Brownian motion for ultrasensitive biomolecule detection.
• To develop a method for quantifying tumor necrosis factor-alpha at trace concentrations.
• To establish a power-free and feasible platform for early disease detection.

Main Methods:

• Janus particles functionalized with antibodies were used to capture tumor necrosis factor-alpha.
• Rotational diffusion of functionalized Janus particles was measured via blinking signals.
• Optimization of light source, stabilization time, and purification was performed.
• Particle imaging was conducted using green light at 5 Hz within 300 s.

Main Results:

• The functionalized Janus particles demonstrated high sensitivity to changes in particle volume.
• A limit of detection of 1 pg/mL for tumor necrosis factor-alpha was achieved.
• The method proved effective for ultrasensitive detection of trace biomolecules.

Conclusions:

• Rotational diffusometry using Janus particles offers a power-free and ultrasensitive detection approach.
• This technique holds significant potential for early disease detection.
• The method provides a novel platform for quantitative analysis of cytokines and other biomarkers.