Naked eye biosensors for pathogen monitoring

Naked-eye biosensors, commonly known as colorimetric biosensors, are highly regarded for their ease of preparation, operation, deliverability, and cheap instrumentation. These strategies rely on observing color changes of a reagent in the presence or absence of a target analyte. These alterations can be easily detected by the naked eye without the need for additional instruments or with simple detectors like smartphones. These benefits have made naked-eye bioassays one of the most investigated testing devices in various fields, including clinical, biochemistry, chemical, and environmental surveys. Pregnancy assessment tools and on-site bacteria monitoring are the most well-known commercially available colorimetric testing devices. In this review, we'll begin by exploring conventional methods before delving into the world of naked-eye biosensors for bioanalysis. This realm encompasses simple colorimetric techniques and lateral flow assays. We'll place a special spotlight on how nanomaterials can be harnessed to improve both the practicality and effectiveness of these bioassays.