A label-free ECL aptasensor for sensitive detection of carcinoembryonic antigen based on CdS QDs@MOF and TEOA@Au as bi-coreactants of Ru(bpy)32+

Herein, a label-free electrochemiluminescence (ECL) biosensor for sensitive determination of carcinoembryonic antigen (CEA) was fabricated based on CdS quantum dots loaded onto metal organic framework (CdS QDs@MOF) and triethanolamine modified on gold nanoparticles (TEOA@AuNPs) as bi-coreactants of Ru(bpy) 3 2+ ECL system. The TEOA@AuNPs served as not only coreactant of Ru(bpy) 3 2+ but also nanocarrier for CEA aptamer which was bonded to the TEOA@AuNPs through Au–S bond. After incubated in CEA solution, the ECL signals decreased due to the poor conductivity of CEA and there was a linear correlation between the ECL intensity and log(C CEA ). Based on this result, a label-free ECL biosensor has been developed successfully and used to detect CEA with a detection limit of 8.5 × 10 −5 ng/mL. The proposed ECL aptasensor had good analytical performance in the detection of CEA in human serum samples.