Electrochemiluminescence resonance energy transfer of MnCO3 for ultrasensitive amyloid-β protein detection

A composite material MnCO3/poly(diallyl dimethyl ammonium chloride) (PDDA)/Ag with excellent electrochemiluminescence (ECL) performance and high biocompatibility was prepared by adding MnCO3 and PDDA to silver nanoparticles (AgNPs). MnCO3/PDDA/Ag and Au@SiO(2)NPs were used as ECL donors and acceptors, respectively. Thus, an effective ECL-resonance energy transfer (RET) sensing platform was established. In a potassium persulfate (K2S2O8) medium, MnCO3 exhibited ECL emission with an ECL band appearing at 500-600 nm. In addition, Au@SiO2 nanoparticles showed a UV-visible absorption at 450-650 nm. The ECL emission spectra of MnCO3 overlapped with the absorption spectra of Au@SiO(2)NPs. The effective ECL quenching resulted in a good response to the concentration of A beta(42) in serum samples. The linear range was 5 fg . mL(-1) to 100 ng . mL(-1), and the detection limit was 2 fg . mL(-1). The recovery ranged from 97.7% to 104%. The high-efficiency ECL-RET immunosensor has potential application in detecting human serum A beta(42) and other biomarkers, and can be used for the early screening of diseases.