A Review of the Application of Nanotechnology in the Diagnosis of Infectious Diseases

Abstract

Infectious diseases caused by bacteria, viruses, fungi, and parasites continue to impose substantial global health burdens, particularly in low- and middle-income countries. Accurate and timely diagnosis remains essential for appropriate treatment, transmission control, and outbreak management. Although conventional diagnostic techniques such as microscopy, culture and serological assays are integral to clinical practice, they are often limited by delayed results, reduced sensitivity during early infection, high operational costs, and dependence on advanced laboratory infrastructure. Nanotechnology enhances diagnostic capability by exploiting the distinctive physicochemical properties of nanoscale materials. Gold and silver nanoparticles, quantum dots, magnetic nanoparticles, carbon nanotubes, graphene, and polymeric nanoparticles possess optical, electrical, magnetic, and catalytic characteristics suitable for bio-sensing, functionalization with antibodies, aptamers, DNA probes, or peptides enables selective detection of pathogen-associated biomarkers. The high surface-area-to-volume ratio of these materials improves binding efficiency, thereby increasing analytical sensitivity and facilitating detection at low pathogen concentrations. In viral diagnostics, nanotechnology supports rapid and sensitive identification of pathogens such as HIV, influenza viruses, hepatitis viruses, Ebola virus, and respiratory viruses. Gold nanoparticle-based lateral flow assays provide rapid visual detection, nano-enhanced PCR improves amplification efficiency, and quantum dots enable multiplex analysis within a single assay. In bacterial detection, magnetic nanoparticles allow efficient pathogen isolation from complex samples, while electrochemical nanosensors incorporating graphene or carbon nanotubes facilitate identification of toxins and antimicrobial resistance markers. Applications in parasitic and fungal diagnostics include improved detection of malaria antigens, Leishmania DNA, and fungal cell wall components through enhanced signal amplification.