Materials-Functionalized Point-of-Care Testing Devices for Pathogen Detection

Pathogen infection can lead to deterioration of physical fitness, organ function decline, and even death, and the continuous interhuman transmissions contribute to the epidemic outbreak. The rapid and sensitive detection of pathogens in clinical samples at scale thus becomes critical to infectious disease screening and containing outbreaks. Traditional detection methods, including microbial culture and polymerase chain reaction (PCR) technologies, involve bulky instrumentation in centralized laboratories, professional technicians, and a lengthy assay time, hence severely hampering the suppression of infection chains and disease treatment. Advanced diagnostic technologies capable of rapidly identifying pathogens are therefore ideal for prompting infection diagnosis and precision medicine. Point-of-care testing (POCT) devices, usually consisting of recognition elements and signal transduction units, offer a promising alternative as they can detect pathogens specifically and give qualitative results within a short time. By overcoming the issues of time-consuming growth culture and complex sample treatment, POCT devices can remarkably expedite the sample-to-result time of infection diagnosis with high sensitivity, thus allowing clinicians to quickly make decisions. Recent years have seen major progress in the development of functional materials that show unique physical and chemical properties to facilitate the performance enhancement of POCT devices, including inorganic nanomaterials, organic polymers, biomaterials, and the like. By contributing to the biorecognition and transduction of biological binding events into electrical and optical readout, functional materials at the interfaces between POCT sensors and the biological samples enable measurements with higher sensitivity and selectivity and faster responses. Hence, the development of high-performance functional materials is expected to increase the microbial detection efficiency of POCT devices by simplifying sample handling and improving the accuracy, thereby aiding in the on-site and real-time detection of pathogens and the large-scale screening of infectious diseases. In this Account, to clarify the potential of POCT devices coupled with functional materials in the rapid diagnosis of infectious diseases, we summarized the applications of materials-engineering-based POCT devices for human pathogen detection in terms of the types of functional materials, such as magnetic materials, metallic materials, luminescent materials, functional nucleic acids, and so forth. Based on our previous studies, we highlighted the abilities of functional materials-assisted POCT devices to detect pathogens in multiple actual biological samples, including urine, saliva, blood, stool, and so on. These applications provide substantial benefits for pathogen diagnostics with regard to fast response, high sensitivity, ease of use, portability, and low cost. Finally, the challenges and future directions of functional materials for POCT devices aimed at clinical pathogen detection are also briefly summarized.