Rapid and quantitative detection of C-reactive protein based on quantum dots and immunofiltration assay.
Convenient and rapid immunofiltration assays (IFAs) enable on-site "yes" or "no" determination of disease markers. However, traditional IFAs are commonly qualitative or semi-quantitative and are very limited for the efficient testing of samples in field diagnostics. Here, we overcome these limitations by developing a quantum dots (QDs)-based fluorescent IFA for the quantitative detection of C-reactive proteins (CRP). CRP, the well-known diagnostic marker for acute viral and bacterial infections, was used as a model analyte to demonstrate performance and sensitivity of our developed QDs-based IFA. QDs capped with both polyethylene glycol (PEG) and glutathione were used as fluorescent labels for our IFAs. The presence of the surface PEG layer, which reduced the non-specific protein interactions, in conjunction with the inherent optical properties of QDs, resulted in lower background signal, increased sensitivity, and ability to detect CRP down to 0.79 mg/L with only 5 µL serum sample. In addition, the developed assay is simple, fast and can quantitatively detect CRP with a detection limit up to 200 mg/L. Clinical test results of our QD-based IFA are well correlated with the traditional latex enhance immune-agglutination aggregation. The proposed QD-based fluorescent IFA is very promising, and potentially will be adopted for multiplexed immunoassay and in field point-of-care test.
Center for Translational Medicine, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China.
Pengfei
P
Zhang
Center for Translational Medicine, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China.
Yan
Y
Bao
Zhejiang-California International Nanosystems Institute, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China ; Faculty of Science, Tanta University, Tanta, Egypt.
Mohamed Shehata
MS
Draz
Center for Translational Medicine, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China.
Huiqi
H
Lu
Center for Translational Medicine, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China.
Chang
C
Liu
Center for Translational Medicine, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China.
Huanxing
H
Han
D002097:C-Reactive Protein / Q000032:analysis*; D005374:Filtration; D005978:Glutathione / Q000737:chemistry; D016174:Hepacivirus / Q000302:isolation & purification; D006515:Hepatitis B virus / Q000302:isolation & purification; D019694:Hepatitis B, Chronic / Q000097:blood / Q000175:diagnosis* / Q000821:virology; D006526:Hepatitis C / Q000097:blood / Q000175:diagnosis* / Q000821:virology; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D019095:Point-of-Care Systems; D011092:Polyethylene Glycols / Q000737:chemistry; D045663:Quantum Dots
D011092:Polyethylene Glycols; D002097:C-Reactive Protein; D005978:Glutathione
C-reactive proteins; Glutathione capped QDs; PEGylation; point-of-care test