A New Colorimetric Platform for Protein Detection Based on Recognition-Induced Cascade of Polymeric Nanoparticles Disassembly.

Despite great progress, it is still of high interest to explore new homogeneous assays for simple, visual, and selective protein detection. Herein, one new colorimetric sensor has been developed for visual detection of protein by using polymeric micelles as a sensing scaffold and the molecular recognition between protein and the ligand on the surface of the polymeric micelles as the driving force to trigger the readout of the detection signal. The polymeric micelles formed via the self-assembly of the amphiphilic block polymer biotin-labeled poly(ethylene glycol)-block-poly(3-acryl aminophenylboronic acid) are endowed with colorful feature by incorporation of alizarin red S (ARS) into the hydrophobic core. Based on the response to streptavidin recognition, these micelles are further disintegrated through the competitive binding of α-cyclodextrin with boronic acid for disassociation of ARS, which achieves orange-yellow to pink-purple transition in 2 h. This work will open the way to develop one new mix-and-measure, visual, and homogeneous assay.