Electrochemiluminescence resonance energy transfer of MnCO for ultrasensitive amyloid-β protein detection.

A composite material MnCO/poly(diallyl dimethyl ammonium chloride) (PDDA)/Ag with excellent electrochemiluminescence (ECL) performance and high biocompatibility was prepared by adding MnCO and PDDA to silver nanoparticles (AgNPs). MnCO/PDDA/Ag and Au@SiONPs were used as ECL donors and acceptors, respectively. Thus, an effective ECL-resonance energy transfer (RET) sensing platform was established. In a potassium persulfate (KSO) medium, MnCO exhibited ECL emission with an ECL band appearing at 500-600 nm. In addition, Au@SiO nanoparticles showed a UV-visible absorption at 450-650 nm. The ECL emission spectra of MnCO overlapped with the absorption spectra of Au@SiONPs. The effective ECL quenching resulted in a good response to the concentration of Aβ in serum samples. The linear range was 5 fg ⋅ mL to 100 ng ⋅ mL, and the detection limit was 2 fg ⋅ mL. The recovery ranged from 97.7% to 104%. The high-efficiency ECL-RET immunosensor has potential application in detecting human serum Aβ and other biomarkers, and can be used for the early screening of diseases.