Ultrasensitive electrochemiluminescent salbutamol immunoassay with dual-signal amplification using CdSe@SiO2 as label and gold nanoparticles as substrate

摘要: The authors describe a dual signal amplification electrochemiluminescent (ECL) immunoassay for ultrasensitive determination of the β-adrenergic agonist salbutamol (SAL). It is based on use gold nanoparticles (AuNPs) and silica-coated quantum dots type CdSe@SiO2. CdSe@SiO2 (NPs) were synthesized by water-in-oil reversed-phase microemulsion. Amino-modified NPs then prepared used as an ECL probe detection SAL in presence K2S2O8. with their large specific surface carry antigen, facilitate electron transfer improve electrochemical reaction efficiency QDs immunosensor was fabricated coating AuNPs competed antigen binding sites antibody NPs. Under optimized conditions, intensity linearly related to logarithm concentration range from 0.001 1000 ng mL−1, lower limit 0.17 pg mL−1 (at S/N ratio 3). assay has good operational stability, highly sensitive selective. judged possess wider scope that it may be applied many other small molecule analytes which adequate antibodies are available.