A Hybrid Phospholipid Monolayer-Based Interface for Interaction-Enhanced Electrical Detection in Biofluids.

Area of Science:

• Biophysics
• Materials Science
• Analytical Chemistry

Background:

• Charge interactions are critical for signal transduction in biosensors.
• Biofluid environments cause charge screening and nonspecific adsorption, hindering biosensor performance.
• Optimizing sensing interfaces is key to overcoming these limitations.

Purpose of the Study:

• To investigate methods for mitigating charge screening and nonspecific adsorption at sensing interfaces.
• To develop an interfacial model with adjustable surface charge for improved signal transduction.
• To enhance the sensitivity of electrical biosensing for biomarker detection.

Main Methods:

• Constructed a hybrid phospholipid monolayer (HPM) with adjustable surface charge.
• Utilized molecular dynamics simulations and density-functional theory (DFT) calculations.
• Doped HPM with unsaturated long-chain molecules to modify interface properties.

Main Results:

• Regulating surface charge density and interface composition effectively mitigates counterion screening and nonspecific adsorption.
• Doping HPM with unsaturated molecules enhanced signal transduction capacity.
• Achieved a highly sensitive detection of myocardial injury biomarkers (MIBs) with a limit of detection (LoD) of 0.92 pg/mL.

Conclusions:

• An appropriate surface charge density and conjugated molecule doping are crucial for efficient signal transduction in electrical biosensing.
• The developed sensing interface demonstrates a promising approach for sensitive biomarker detection.
• Understanding interface composition-performance relationships is vital for advancing biosensor technology.