Embracing Nature's Wisdom: Liposome-Mediated Amplification of Electrochemiluminescence for the Sensitive and Selective Immunoassay of Serum Amyloid A.

Serum amyloid A (SAA) is a key biomarker for diagnosing inflammatory responses in diseases like influenza and COVID-19. An electrochemiluminescence (ECL) biosensor has been constructed for signal enhancement in SAA detection by encapsulating 4,4',4″,4‴-(1,3,6,8-pyrenetetrayl) tetrakis-benzoic acid (TBAPy) into liposomes. Such biomimetic encapsulation shields the biologically important membrane to avoid aggregation of TBAPy and prevents quenching. It would enhance the ECL signal's stability and intensity, resulting in a 5-fold signal increase with a relative standard deviation (RSD) of 1.71%. The biosensor has shown very good specificity and sensitivity toward SAA detection. The estimated detection limit is 0.188 pg/mL. This innovative approach integrates biomimicry with ECL technology and represents a leap in developing the next generation of diagnostic tools with superior sensitivity and specificity.