Seeking Solutions for Inclusively Economic, Rapid, and Safe Molecular Detection of Respiratory Infectious Diseases: Comprehensive Review from Polymerase Chain Reaction Techniques to Amplification-Free Biosensing

Abstract

Frequent outbreaks of respiratory infectious diseases, driven by diverse pathogens, have long posed significant threats to public health, economic productivity, and societal stability. Respiratory infectious diseases are highly contagious, characterized by short incubation periods, diverse symptoms, multiple transmission routes, susceptibility to mutations, and distinct seasonality, contributing to their propensity for outbreaks. The absence of effective antiviral treatments and the heightened vulnerability of individuals with weakened immune systems make them more susceptible to infection, with severe cases potentially leading to complications or death. This situation becomes particularly concerning during peak seasons, such as influenza outbreaks. Therefore, early detection, diagnosis, and treatment are critical, alongside the prevention of cross-infection, ensuring patient safety, and controlling healthcare costs. To address these challenges, this review aims to identify a comprehensive, rapid, safe, and cost-effective diagnostic approach for respiratory infectious diseases. This approach is framed within the existing hierarchical healthcare system, focusing on establishing diagnostic capabilities at hospitals, community, and home levels to effectively tackle the above issues. In addition to PCR and isothermal amplification, the review also explores emerging molecular diagnostic strategies that may better address the evolving needs of respiratory disease diagnostics. A key focus is the transition from amplification technologies to amplification-free biosensing approaches, with particular attention given to their potential for home-based testing. This shift seeks to overcome the limitations of conventional amplification methods, particularly in decentralized and home diagnostics, offering a promising solution to enhance diagnostic speed and safety during outbreaks. In the future, with the integration of AI technologies into molecular amplification technologies, biosensors, and various application levels, the inclusively economic, rapid, and safe respiratory disease diagnosis solutions will be further optimized, and their accessibility will become more widespread.

Keywords: amplification-free biosensing; full scene solution; isothermal amplification; molecular detection of respiratory infectious diseases; polymerase chain reaction; tiered diagnosis.

Figure 3

Spatial-domain PCR. (a) Changes in a spatial physical location; (b) external force-driven continuous spatial flow via a syringe pump; (c) equivalent thermal resistance diagram; (d) magnetic field-driven continuous flow; (e) circulating ferrofluid-driven flow (adapted from ref. [100]); (f) direct temperature zone contact with ferrofluid for driving flow [101].

Figure 1

Comprehensive molecular diagnosis and treatment solution for respiratory infectious diseases. (a) Hierarchical diagnosis and treatment scenarios for infectious diseases; (b) solutions for different scenarios; and (c) overview of amplification and amplification-free methods.

Figure 2

Temporal-domain PCR. (a) Traditional thermoelectric cooler; (b) integration of TEC and PCR chamber; (c) resistive heating; (d) direct heating via electromagnetic waves; (e) indirect heating via electromagnetic waves with heat removal through flow; (f) direct heating and cooling via electromagnetic wave-induced nanoparticles [25] (g) electromagnetic wave-induced metal heating.

Figure 4

Spatiotemporal unified PCR, isothermal amplification, and biosensors. (a) Closed-loop convective PCR; (b) circular raceway convective PCR; (c) capillary convective PCR; (d) isothermal amplification; (e) biosensor; (f) convective PCR thermal resistance analysis diagram.

Figure 5

Transition from amplification-based to amplification-free technologies. (a) Steps and reagent components of amplification technology; (b) steps and sensor components of biosensor technology.

Figure 6

Traditional three-zone PCR laboratory in hospitals. (a) Reagent preparation zone; (b) sample processing zone; (c) PCR amplification and result analysis zone.

Figure 7

Hospital-based molecular infectious disease detection solutions. (a) Reagent preparation zone; (b) semi-automated nucleic acid extraction solution; (c) PCR amplification and result analysis zone; (d) fully automated nucleic acid extraction; (e) integrated molecular infectious disease detection system; (f) intelligent molecular infectious disease detection laboratory.

Figure 8

Molecular POCT system. (a) Reagent preparation area; (b) sample preparation area; (c) amplification and analysis area; (d) microfluidic cartridge; (e) POCT instrument.

Figure 9

Application scenarios for home-based molecular testing products.

Figure 10

Development trends of molecular diagnostic technologies for respiratory infectious diseases in various application scenarios.