Unlocking interstitial fluid for acute coronary syndrome diagnosis: ultrasensitive troponin I detection using...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Clinical Diagnostics

Background:

• Acute coronary syndrome (ACS) diagnosis relies on cardiac biomarkers like cardiac troponin I (cTnI).
• Current detection methods often require invasive blood draws and can be time-consuming.
• Interstitial fluid (ISF) offers a potential alternative biofluid for non-invasive biomarker monitoring.

Purpose of the Study:

• To develop and validate a novel biosensor for the rapid and sensitive detection of cTnI in human interstitial fluid (ISF).
• To assess the feasibility of using ISF collected via electroporation for point-of-care ACS diagnosis.
• To compare the performance of the developed sensor with conventional methods using plasma and serum samples.

Main Methods:

• Detection of cTnI in ISF using molecularly imprinted polymer nanoparticles as recognition elements.
• Utilized a heat-transfer method within a microfluidic system for rapid measurements (15-20 min).
• ISF was collected non-invasively using electroporation, followed by cTnI quantification.

Main Results:

• Achieved a highly sensitive detection limit of 1.85 ± 0.32 pg mL⁻¹ for cTnI in spiked ISF.
• Demonstrated reliable quantification across a wide concentration range (0.1–1000 pg mL⁻¹).
• Similar low detection limits were observed in spiked plasma and serum samples, validating the sensor's performance.

Conclusions:

• The developed sensor provides a rapid, highly sensitive, and non-invasive method for cTnI detection in ISF.
• This platform is suitable for point-of-care ACS diagnosis, potentially improving patient outcomes.
• The approach offers a cost-effective alternative to conventional diagnostic methods, reducing healthcare burdens.