Nano-modified biosensors for detection of pathogenic diseases: The prospect of smart, multiplex and point-of-care testing

The world has witnessed several outbreaks, emergence and re-emergence of infectious diseases throughout the 21^st century as a result of climate change, urbanization and migration. Several infectious diseases caused by pathogens such as SARS-CoV-2, Ebola, Zika, Dengue, Marburg viruses, Mycobacterium tuberculosis, etc. have caused a devastating impact on lives and livelihoods around the world. To counter these diseases, medical experts rely on conventional techniques, which include microscopy and serological testing. However, these conventional methods are hindered by several trade-offs, including high cost, longer processing times, low sensitivity, and a likelihood of false positive results. Biomedical sensors have gained momentum in clinical diagnostics due to their low cost, portability, and sensitivity, among other advantages. To improve their performance, scientists have incorporated nanomaterials. Other techniques used to enhance the performance of nanobiosensors include multiplex testing, point-of-care testing (POCT), and smart sensing.

Thus, in this review, we present a comprehensive overview of the state-of-the-art nanobiosensors for detecting infectious diseases. The review covers key topics that are centred around the application of nanotechnology in biosensing, multiplex testing, POCT and smart nano-enhanced biosensors.

The findings of this review highlighted the advantages of biosensors over conventional approaches, with a limit of detection ranging from nanomolar to attomolar concentrations and a time response ranging from 1 to 3 hours.

Despite the prospect of nanobiosensors, several limitations exist, including complexity, extensive processing time, and others. Moreover, the integration of smart technologies in nanobiosensors can offer several benefits, including high accuracy and faster detection and prediction.