<p>Polymerization-induced self-assembly (PISA) is a revolutionary cutting-edge technology for biomolecular detection, overcoming the low solid content problems faced by traditional block copolymer self-assembly methods. By integrating simultaneous polymerization and assembly, this approach offers significantly higher copolymer concentrations than traditional methods. Among them, reversible addition-fragmentation chain transfer (RAFT) and atom transfer radical polymerization (ATRP) are the most widely used polymerization methods. As a new type of polymer self-assembly technology, products obtained by PISA technology have better stability, plasticity, and biocompatibility than those obtained by traditional methods. This review mainly introduces the principles of various common free radical polymerization reactions and the PISA polymers prepared by these methods, which are expected to be widely used in molecular detection. The target detection objects include biological molecules such as proteins, enzymes, and nucleic acids. At the end of the article, some prospects for the future development of PISA technology are also discussed. It is hoped that this review can provide a reference for researchers in the field of PISA and further promote the research progress in polymer self-assembly.</p>