Controlled/"living" radical polymerization-based signal amplification strategies for biosensing. Issue 16 (19th December 2019) - Hu, Qiong
Abstract : Controlled/"living" radical polymerization-based signal amplification strategies and their applications in highly sensitive biosensing of clinically relevant biomolecules are reviewed. Abstract : Controlled/"living" radical polymerization (CLRP) techniques, such as atom transfer radical polymerization (ATRP), reversible addition–fragmentation chain transfer (RAFT) polymerization, and their variants, have now emerged as a novel class of signal amplification strategies and they have attracted growing attention in biosensing of clinically relevant biomolecules. Through the CLRP-mediated de novo formation of polymer chains, a large amount of signaling probes ( e.g., ferrocene) or functional groups ( e.g., –NH2, –CHO, and –COOH) that are available for the subsequent introduction of signaling probes can be recruited in the sensing interfaces, outputting a high signal even in the presence of a low abundance of target analytes, thereby greatly improving the detection sensitivity. Compared with conventional strategies based on the use of either catalytic labels ( e.g., natural enzymes, biomimetic catalysts, and electrocatalysts) or complex nanomaterials ( e.g., surface-functionalized metal nanoparticles), CLRP-based signal amplification strategies have advantages of being low-cost, highly efficient, and relatively easy in operation. By virtue of these merits, CLRP-based signal amplification strategies show great promise for clinical applications and biomedical research studies. In this review, the advantages and disadvantages of various signal amplification strategies have been summarized. Following a brief introduction of the mechanisms of various CLRP techniques, a comprehensive overview of the applications of CLRP-based signal amplification strategies in biosensing of clinically relevant biomolecules such as nucleic acids, enzymes, and antigens is presented. Also discussed herein are the advantages and disadvantages of CLRP-based signal amplification strategies, which are believed to be instructive for their broad application in biosensing.