Journal
INTERNATIONAL JOURNAL OF NANOMEDICINE
Volume 13, Issue -, Pages 2521-2530Publisher
DOVE MEDICAL PRESS LTD
DOI: 10.2147/IJN.S154046
Keywords
colorimetric assay; gold nanoparticles; prostate-specific antigen; ascorbic acid; Cu2+ ion
Funding
- National Natural Science Foundation of China [21305004]
- Program for Science and Technology Innovation Talents at the University of Henan Province [18HASTIT005]
- Joint Fund for Fostering Talents of National Natural Science Foundation of China [U1304205]
- Science & Technology Foundation of Henan Province [17A150001]
- Program for Innovative Research Team of Science and Technology in the University of Henan Province [16IRT-STHN003]
- Joint Fund for Fostering Talents of National Natural Science Foundation of Henan Province [U1304205]
Ask authors/readers for more resources
Background: Prostate-specific antigen (PSA), a serine protease, is a biomarker for preoperative diagnosis and screening of prostate cancer and monitoring of its posttreatment. Methods: In this work, we reported a colorimetric method for clinical detection of PSA using gold nanoparticles (AuNPs) as the reporters. The method is based on ascorbic acid (AA)-induced in situ formation of AuNPs and Cu2+-catalyzed oxidation of AA. Specifically, HAuCl4 can be reduced into AuNPs by AA; Cu2+ ion can catalyze the oxidation of AA by O-2 to inhibit the formation of AuNPs. In the presence of the PSA-specific peptide (DAHSSKLQLAPP)-modified gold-coated magnetic microbeads (MMBs; denoted as DAHSSKLQLAPP-MMBs), complexation of Cu2+ by the MMBs through the DAH-Cu2+ interaction depressed the catalyzed oxidation of AA and thus allowed for the formation of red AuNPs. However, once the peptide immobilized on the MMB surface was cleaved by PSA, the DAHSSKLQ segment would be released. The resultant LAPP fragment remaining on the MMB surface could not sequestrate Cu2+ to depress its catalytic activity toward AA oxidation. Consequently, no or less AuNPs were generated. Results: The linear range for PSA detection was found to be 0 similar to 0.8 ng/mL with a detection limit of 0.02 ng/mL. Because of the separation of cleavage step and measurement step, the interference of matrix components in biological samples was avoided. Conclusion: The high extinction coefficient of AuNPs facilitates the colorimetric analysis of PSA in serum samples. This work is helpful for designing of other protease biosensors by matching specific peptide substrates.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available