Sensitive Fluorescence Analysis of Pregnancy Plasma Associated Protein A in Amniotic Fluid Based on the Plasma Superstructure Enhanced Carbon Polymer Dots

Abstract

Early detection of serum pregnancy plasma associated protein A can provide guidance for diagnosis and treatment of pregnancy-related diseases. However, the current immune-based analysis methods are complicated, time-consuming, low sensitivity and other problems. Therefore, based on the advantages of simple, rapid and sensitive nano-biosensor, we designed a highly sensitive fluorescent biosensor for monitoring PAPP-A in amniotic fluid of pregnant women. The signal-to-noise ratio and sensitivity are further improved based on the principle of plasma enhanced fluorescence. The specific design scheme is to synthesise wavelength matching plasma superstructure Ag@Au and fluorescence based carbon polymer dots, and modify them with monoclonal antibody IgG and specific antibody, respectively. Sandwich plasma enhanced fluorescence structure is formed under the action of the target for PAPP-A specific sensitive detection. The linear response in the range of 1–50 μg/mL and the detection limit of 0.02 μg/mL were achieved. The sensor has also been successfully used for the accurate analysis of PAPP-A in amniotic fluid samples, which has certain practical application value.