A liquid-crystal-based immunosensor for the detection of cardiac troponin I

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Cardiac troponin I (cTnI) is a critical biomarker for diagnosing myocardial infarction (MI) and acute coronary syndrome (ACS).
• Current diagnostic methods require sensitive and specific detection of cTnI to identify even minor myocardial damage.
• There is a need for advanced biosensors with improved sensitivity, specificity, and cost-effectiveness.

Purpose of the Study:

• To develop and demonstrate a label-free biosensor for the sensitive and specific detection of cardiac troponin I (cTnI).
• To utilize the unique optical properties of nematic liquid crystals (LCs) for signal transduction in biosensing applications.
• To establish a cost-effective and facile platform for early diagnosis of myocardial injury.

Main Methods:

• A label-free biosensor was engineered using the birefringence of nematic liquid crystals (LCs).
• A substrate was coated with a chemically sensitive film enabling specific molecular recognition.
• The interaction between cTnI antigen-antibody complexes altered the orientation of LC molecules, detected via polarized optical microscopy.

Main Results:

• The biosensor successfully detected cTnI with high sensitivity, achieving a low detection limit of 1 pg/mL.
• The device exhibited excellent specificity due to the antigen-antibody binding mechanism.
• A distinct optical signal change (from dark to bright) was observed upon cTnI detection.

Conclusions:

• The developed liquid crystal-based immunosensor provides a sensitive, specific, and cost-effective method for cTnI detection.
• This facile biosensor platform holds significant promise for the rapid diagnosis of acute myocardial infarction and related cardiac conditions.
• The study highlights the potential of LC-based biosensors in advancing biomedical diagnostics.