Ultrasensitive Sensor Detects Early Stages of Diseases

A prototype ultrasensitive sensor has been developed that would enable doctors to detect the early stages of diseases and viruses with the naked eye.

The sensor works by analyzing serum, derived from blood, in a disposable container. If the result is positive for p24, a biomarker that indicates Human Immunosuppressant Virus (HIV) infection, or for Prostate Specific Antigen (PSA), an early indicator for prostate cancer, there is a reaction that generates irregular clumps of nanoparticles, which give off a distinctive blue hue in a solution inside the container. If the results are negative, the nanoparticles separate into ball-like shapes, creating a reddish hue. Both reactions can be easily seen by the naked eye.


The scientific team, from Imperial College London, (United Kingdom) reported that their visual sensor technology is ten times more sensitive than the current gold standard methods for measuring biomarkers. These indicate the onset of various diseases and viral infections. The team said that the sensor can be reconfigured for other viruses and diseases if the specific biomarker is known. The sensor should benefit countries where sophisticated detection equipment is scarce, enabling cheaper and simpler detection, and treatments for patients.

Prof. Molly Stevens, from the departments of materials and bioengineering at Imperial College London, said, “It is vital that patients get periodically tested in order to assess the success of retroviral therapies and check for new cases of infection. Unfortunately, the existing gold standard detection methods can be too expensive to be implemented in parts of the world where resources are scarce. Our approach affords for improved sensitivity, does not require sophisticated instrumentation and it is ten times cheaper, which could allow more tests to be performed for better screening of many diseases.”

The study was reported in the October 2012 journal Nature Nanotechnology.

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Imperial College London