Quantitative Detection of Procalcitonin in Blood by Nanozyme-based Lateral Flow Immunoassay

A rapid quantitative immunochromatographic assay for procalcitonin (PCT) using metal-organic frameworks modified with gold and platinum nanoparticles (MAPs) as labels was established in this work. The detection probe was prepared by conjugating MAPs with anti-PCT monoclonal antibody via an electrostatic adsorption method. Anti-PCT polyclonal antibody and sheep anti-mouse IgG were sprayed onto the nitrocellulose (NC) membrane as the test line and quality control line, respectively, to construct immunochromatographic strip for PCT quantitative detection via signal-amplification-based sandwich immunoassay. The results showed that the MAP-based immunochromatographic test had high sensitivity, high specificity, and good stability. The dynamic range for detection of PCT was 0.61 pg/mL-320 ng/mL, the detection limit was 0.25 pg/mL, and the intra-day and inter-day precision (Relative standard deviation) were less than 15%. The results of real sample analysis showed that a quite low volume of sample was required for detection of PCT in whole blood, which was of great significance for the early diagnosis, monitoring and treatment, and prognosis of inflammation.