Viruses originating from birds and animals are known as zoonotic viruses. When these viruses are transmitted to humans through direct or indirect contact with infected populations, they cause a zoonotic spillover. Approximately 70% of infectious diseases over the last three decades are zoonotic. Because no immediate diagnosis or effective cure is available for the new virus, outbreaks, epidemics, and pandemics are likely to spread rapidly.

Background

Such viruses include Influenza A, Ebola, and three coronaviruses. Coronaviruses (CoV) have caused life-threatening epidemics such as severe acute respiratory syndrome (SARS)-CoV and the Middle East respiratory syndrome (MERS)-CoV in the last five decades. The ongoing COVID-19 (coronavirus disease 2019) pandemic is one such zoonotic virus that has rapidly caused over 211 million infections and over 4.43 million deaths worldwide since December 2019. The severe acute respiratory syndrome virus (SARS-CoV-2), the etiological agent of COVID-19, is a novel coronavirus strain transmitted by mammals.

Viruses and nanoparticles are in a comparable size range. The latter having attractive properties such as small size, large surface-to-volume ratio, susceptibility to modification, and intrinsic viricidal activity. Therefore, scientists functionalize nanoparticles to act against these pathogenic viruses in a clinical strategy. In a recent review published in the journal Microbial Pathogenesis, researchers look at the novel solutions against zoonotic viruses provided by nanotechnology.

Nanomaterials are described as ‘materials containing structural nanoelements which considerably improve or cause qualitatively new physical, chemical, biological, mechanical, and other properties.’ Excellent properties like the high surface area to volume ratio, high thermal conductivity, and faster signal transduction make the nanomaterials useful in clinical and biomedical applications. For example, nanomaterials in viral diagnostics have advanced sensitivity, the capability of multiplexing, and cost-effectiveness.

Detection of viruses

Rapid and reliable diagnostics is crucial to defend against any viral outbreak, especially in the case of a highly virulent strain. Conventional molecular diagnostic techniques rely on the amplification of the viral nucleic acids. However, these methods are time-consuming processes with lower specificity and accuracy – nanotechnology can remarkably address the challenges. Immobilizing specific ligands on the nanometric scale, nanotechnology is employed for molecular imaging and profiling in diagnostics.

Nanosensors, for rapid biosensing of virus-associated proteins, are advances in nanotechnology that are widely employed. Nano-sensors are nanoparticle-based devices that can sense signals at a nanoscale comprising three major components; a signal transducer, a receiver, and a detector with a monitoring output.  Using these highly sensitive nano-sensors along with other analyzing instruments increases the detection efficiency and also helps deal with the point-of-care type (POCT) pervasive detection systems.

Novel magnetic relaxation nanosensors are used to rapidly detect influenza-associated proteins, adenovirus, and Herpes simplex virus (HSV). Few examples include: multiplex colorimetric paper-based analytical devices using silver nanoparticles can detect MERS-CoV, gold nanoparticles and quantum dots stain for HPV (Human papillomavirus), and chiroimmunosensors can detect infectious bronchitis virus.