Aminopolycarboxyl-modified Ag2S nanoparticles: Synthesis, characterization and resonance light scattering sensing for bovine serum albumin

A novel method was proposed to prepare a series of functionalized Ag2S nanoparticles capped with various aminopolycarboxylic acids. The as-prepared Ag2S nanoparticles were characterized by UV–vis, FTIR, resonance light scattering spectra (RLS) and transmission electron microscopy (TEM). Based on the RLS intensities enhanced by BSA-induced Ag2S nanoparticles aggregation, a sensitive RLS method for the detection BSA at nanogram levels was established. The detection limits for BSA are between 8.6 and 112.6 ng mL−1, depending on the different capping agents. The effects of various capping agents on the detection limits of BSA have been investigated. The detection limit is found to be dependent on the stability constant (log KMY) of the silver–aminopolycarboxyl complexes.