Nanomaterials-based electrochemical immunosensors for proteins

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Biomedical Engineering

Background:

• Polarography has a 90-year history in electrochemical analysis.
• Protein determination is crucial for cancer detection and monitoring.
• Nanoparticle labels and multiplexed detection are recent advances in protein immunosensors.

Purpose of the Study:

• To describe the development of ultrasensitive protein immunosensors.
• To review recent advancements in nanoparticle-labeled protein detection.
• To present a microfluidic device for multiplexed protein detection in cancer diagnostics.

Main Methods:

• Combining nanostructured electrodes with enzyme-labeled nanoparticles (up to 500,000 enzymes per particle).
• Developing a microfluidic device with eight sensors coated with 5-nm gold nanoparticles.
• Utilizing off-line protein detection with heavily labeled magnetic particles.

Main Results:

• Achieved ultrasensitive protein detection down to 1 fg/mL in diluted serum.
• Demonstrated reliable sub-picogram/mL detection limits for multiple proteins.
• Obtained excellent correlation with referee Enzyme-Linked Immunosorbent Assay (ELISA) methods.

Conclusions:

• The developed ultrasensitive protein immunosensors show promise for early cancer detection and monitoring.
• The microfluidic device enables reliable, multiplexed detection of cancer biomarkers.
• This technology is currently undergoing validation for oral and prostate cancer biomarkers.