In this work, a sensitive signal-on electrochemiluminescence
biosensor
using liposome-encapsuled 1,1,2,2-tetra(4-carboxylphenyl)ethylene
(TPE) as a promising aggregation-induced electrochemiluminescence
(AIECL) emitter for detection of biomarkers was developed. Aggregation-induced
enhancement occurs internally through the spatial confinement effect
and intramolecular self-encapsulation of encapsulating TPE and triethylamine
(TEA) molecules in liposome cavities. Peptide sequence WTGWCLNPEESTWGFCTGSF
(WF-20) was used to replace the antibody for reducing the steric hindrance
of the sensing surface while taking into account the affinity. The
proposed sensing strategies showed satisfactory properties for detection
of human epidermal growth factor receptor 2 (HER2) ranging from 0.01
to 500 ng/mL with a limit of detection of 6.65 pg/mL. The results
confirmed that encapsulation of luminescent molecules in the vesicle
structure for triggering the AIECL phenomenon is a promising method
to prepare a signal label for a trace detection biomarker.