Electrochemical immunoassay for the detection of IgM antibodies using polydopamine particles loaded with PbS quantum dots as labels.
Here, we report for the first time, an electrochemical immunoassay to detect IgM antibodies using lead sulfide quantum dots (PbS QDs) as electrochemical labels. In this sense, dendritic-like polydopamine particles loaded with PbS QDs were synthesized by the self-polymerization of dopamine in basic media in the presence of QDs (PbS@PDA) and further tagged with anti-IgM antibodies, dengue specific antigens, and streptavidin moieties. The analytical features of the sandwich immunoassay on ELISA microplate were carried out with the PbS@PDA-labeled anti-IgM as secondary antibody. The system was interrogated by acid dissolution of PbS@PDA, followed by differential pulse anodic stripping voltammetry in the presence of Bi(III) ions using carbon screen-printed electrodes. The results indicate that the voltammetric current increased with the increasing of the concentration of target IgM within a range of 0-0.5 mg mL-1. The limit of detection of this electrochemical immunoassay was evaluated to 130 ng. The measures of satisfactory recoveries from 88.5% to 114% of spiked samples indicate that such a method has good specificity and is applicable to the quantification of IgM antibodies in complex biological samples. No significant differences at the 0.05 significance level were encountered in the analysis of IgM samples between the electrochemical immunoassay and a Bradford assay.
['Ortega|Greter A|GA|', 'Zuaznabar-Gardona|Julio C|JC|', 'Reguera|Edilso|E|']
D000941:Antigens D015374:Biosensing Techniques D001729:Bismuth D002244:Carbon D055664:Electrochemical Techniques D004566:Electrodes D006801:Humans D007118:Immunoassay D007075:Immunoglobulin M D007211:Indoles D007854:Lead D057230:Limit of Detection D053758:Nanoparticles D011108:Polymers D045663:Quantum Dots D044967:Serum D019809:Streptavidin D013440:Sulfides
IgM Polydopamine Quantum dots Stripping voltammetry