Influence of storage time (A), immobilization concentration (B), incubation time (C), and detection antibody concentration (D) on the fluorescence intensity. (A) Fluorescence intensity after different storage times (1-10 d) for the QD-streptavidin stock solution only (black line), QD-mAb stock solution only (red line), and 10 mg/L of the purified CRP standard using QD-mAb (green line). (B) Various coating concentrations (1-10 mg/L) of primary anti-CRP monoclonal antibody were employed, and 10 mg/L of serum hs-CRP was introduced into the detection well to judge the highest fluorescence intensity. (C) In each determination, the serum hs-CRP (10 mg/L) was incubated with 4 mg/L of coating antibody for different time periods (varied from 5-50 min with a 5-min interval) to determine the optimal reaction time. (D) Various coating concentrations (0.1-1 mg/L) of capture antibody were introduced into the microplate (4 mg/L coating antibody) and reacted with 10 mg/L serum CRP. Error bars indicate the standard errors of 3 independent experiments.