A Study on Plasminogen-Ag Nanoparticles Interaction and its Application in Sensor Development

Abstract

The interaction between plasminogen and Ag nanoparticles is studied using different techniques and applied for plasminogen sensor development. Ag nanoparticles are synthesized using an algal extract and their absorbance, emission, and electrochemical oxidation signals are detected and monitored as a function of plasminogen concentration. The variation in the optical and electrochemical properties of Ag nanoparticles is correlated with the changes in the hydrodynamic size of the bioconjugate at different plasminogen concentrations. A steady decrease in the absorbance and electrochemical oxidation peak of Ag nanoparticles is observed, while a threshold plasminogen concentration results in increasing the emission of Ag nanoparticles followed by a steady decrease in signal. The decrease in the optical and electrochemical oxidation signal of Ag nanoparticles agrees with the plasminogen-induced Ag nanoparticle agglomeration shown by dynamic light scattering. Calibration curves are established based on the absorbance, emission, and voltammetric studies obtaining a limit of detection as low as 0.740 nM with a wide linear range of 0.942-18.2 nM, which is a very promising analytical system for plasminogen detection, facilitating its progress as a biomarker for different biomedical applications.