(Colloid. Surf. A: Phys. Eng. Asp.) Magnetic Microspheres with ATRP-synthesized Carboxyl Polymer Brushes for Chemiluminescence Immunoassays
作者：Ma, D.; Chu, X.; Yang, X.; Cai, X.; Hu, S.; Guo, L.*; Wang, Z.*; Yang, H.*
關鍵字：Chemiluminescence Immunoassay
論文來源：期刊
具體來源：Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2025, 726, 137837.
發表時間：2025年
The surface characteristics of magnetic microspheres critically determine their performance in bioseparation
applications including protein purification, enzyme immobilization, nucleic acid extraction, and immunoassays.
To optimize microsphere performance, ATRP-synthesized polymer brushes can be grafted onto their surfaces to
introduce high-density functional groups (e.g., amino, carboxyl, and tosyl groups). This strategy significantly
enhances functional group density by constructing interfaces with extended polymer brushes. This study employs
polymer chains grafting strategy to substantially increase functional group density through long-chain polymer
interfaces on magnetic microspheres, thereby optimizing surface properties and expanding application potential.
Initially, carboxylated polymer chains with controlled molecular weights (5.2–51.2 kDa) are synthesized via
atom transfer radical polymerization (ATRP), followed by strain-promoted azide-alkyne cycloaddition (SPAAC)
for surface grafting. To further suppress non-specific adsorption associated with protein conjugation, we also
design and synthesis binary copolymer brushes, P(GMA-NH-COOH-co-GAMA), incorporating gradient glucose-
based monomers (GAMA). Experimental results demonstrate that ZY-P(G)-1 magnetic microspheres modified
with 10.2 kDa PGMA-NH-COOH polymer brushes exhibit a surface carboxyl group density of 1.384 mmol g
1
.
The bovine serum albumin (BSA) coupling capacity increases to 44.21 mg g
1
, with the chemiluminescence high-
value signal-to-background (S/B) ratio showing a 7.97-fold enhancement compared to conventional carboxyl
microspheres (ZY-COOH). ZY-P(GG)-100:2 microspheres modified with amphiphilic polymers containing 2 mol
% GAMA maintain superior detection sensitivity with 1.74-fold higher S/B ratio than ZY-P(G)-1 while signifi
cantly reducing nonspecific protein adsorption. This study establishes a synergistic engineering approach for
precise surface modification through coordinated optimization of spacer dimensions and functional monomer
ratios. The developed platform significantly enhances the capture efficiency of low-abundance biomarkers,
providing a novel material basis for high-precision in vitro diagnostic reagent development.