Point-of-Care Testing with Nanomaterials

Nanomaterials have been widely employed in the fabrication of novel point-of-care testing (POCT) diagnostics for non-infectious and infectious diseases. Owing to their superior physical, chemical, optical, electrical, thermal, and mechanical properties, nanomaterial-customized POCTs are highly promising for rapid disease diagnosis. The transportation and processing of samples, their high cost, their duration, and the need for specialized personnel to operate them are the main constraints of conventional biochemical and immunological diagnostic techniques. Advanced POCT systems, which are more portable, quick, inexpensive, and automated with simpler detection procedures, overcome these limitations. Promising outcomes have been observed in these devices for the quick identification of various disease biomarkers, such as infectious (pathogen antigens and host antibodies), genomic (DNA, RNA, miRNA, and cancer cells), and proteomic (peptides and lipid metabolites) biomarkers. This chapter describes POCT immunoassays, specifically, the microfluidic, electrochemical, immunochromatographic, and enzyme-linked immunosorbent assays. The biosensing and related POCT utility is given a strong emphasis. In recent years, smart and sustainable nanomaterials, such as carbon nanomaterials (graphene, carbon nanotubes, carbon dots, and quantum dots), noble metal nanoparticles (NPs), mesoporous silica, and upconversion NPs, have been extensively used in POCT devices. The versatile physical and chemical properties of these smart nanomaterials bestow superior detection range, high sensitivity, selectivity, reproducibility, repeatability, and response time to POCT devices. This chapter will describe the recent advances in smart nanomaterial-based POCT devices for the analysis of various disease biomarkers. Existing challenges and future directions of these innovative POCT platforms are also discussed.