Nanotube-based colorimetric probe for ultrasensitive detection of ataxia telangiectasia mutated protein.
We have developed a nanotube-based colorimetric probe using multiwalled carbon nanotubes (MWNTs), anti-immunoglobulin G (anti-IgG), and horseradish peroxidase (HRP). The probe was used as an alternative to conventional colorimetric conjugates to obtain amplified signals in a sandwich-type immunoassay for ataxia telangiectasia mutated (ATM), a potential biomarker for radiation doses and cancers. Results show that the MWNT-based probe colorimetry was 5000 times more sensitive than a conventional ELISA, while its concentration range was 10,000 times wider than that of the latter. Its limit of detection (LOD) was 0.2 fg/mL (54 aM, ~32 molecules in 1 μL samples). Control experiments showed that detection of ATM molecules at the picogram-level could still be achieved in samples that contained protein makers present at more than 100 times the ATM concentration, demonstrating the high specificity of the technique. The MWNT-based probe also has the potential to become a universal probe for colorimetric assays of most protein markers because it can recognize the associated rabbit polyclonal antibodies.
Department of Naval Medicine, Second Military Medical University, Shanghai, 200433, China.
Qingzhi
Q
Zhang
Bin
B
Zhao
Juan
J
Yan
Shiping
S
Song
Rui
R
Min
Chunhai
C
Fan
D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins; D014408:Biomarkers, Tumor / Q000032:analysis / Q000276:immunology; D018797:Cell Cycle Proteins / Q000032:analysis* / Q000276:immunology; D003124:Colorimetry; D004268:DNA-Binding Proteins / Q000032:analysis* / Q000276:immunology; D006735:Horseradish Peroxidase / Q000378:metabolism; D007118:Immunoassay; D007074:Immunoglobulin G / Q000276:immunology; D037742:Nanotubes, Carbon / Q000737:chemistry*; D017346:Protein Serine-Threonine Kinases / Q000032:analysis* / Q000276:immunology; D011817:Rabbits; D025521:Tumor Suppressor Proteins / Q000032:analysis* / Q000276:immunology
D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D007074:Immunoglobulin G; D037742:Nanotubes, Carbon; D025521:Tumor Suppressor Proteins; D006735:Horseradish Peroxidase; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases