Immuno-PCR: Advancements, and applications for infectious diseases diagnosis

Immuno-polymerase chain reaction (I-PCR) is a hybrid technique that combines the specificity of immunoassays with the amplification power of polymerase chain reaction for highly sensitive detection of Infectious Diseases Biomarkers. Since its introduction, I-PCR has evolved through advances such as the introduction of universal streptavidin-biotin systems, nanoparticle-based amplification, magnetic bead-assisted formats and the adoption of real-time and digital PCR readouts. These improvements have enabled detection limits significantly lower than traditional immunoassays, enabling its effective application in detecting viral, bacterial, parasitic, prion, and fungal antigens, as well as host antibodies, with detection limits reaching femtogram levels. However, clinical translation remains restricted by assay complexity, background signal amplification, and the reliance on thermal cyclers and specialized equipment. Future developments focusing on simplifying assay workflows, optimizing DNA-antibody conjugation, implementing isothermal amplification methods, and designing multiplexed point-of-care diagnostic platforms are essential to overcome current limitations. Addressing these challenges through continued innovation is essential to completely harness the potential of I-PCR as a highly sensitive, rapid, and accessible diagnostic platform across diverse healthcare settings.