Researchers from Imperial College London and the University of Vigo, Spain, have developed an ultra-sensitive test to detect the signs of disease in its earliest stages.

The new test is designed to identify particular molecules that indicate the presence of disease, even in very low concentrations, which is not possible with existing biosensors.

The researcher team said that the new biosensor test can find a biomarker associated with prostate cancer, called prostate-specific antigen (PSA).

The biosensors used in the study included nanoscopic-sized gold stars with attached antibodies floating in a solution containing other blood derived proteins, to detect PSA at 0.000000000000000001g per millilitre, which is at the limits of current biosensor performance.

"The new biosensor test can find a biomarker associated with prostate cancer."

The team demonstrated the effectiveness of the new biosensor test by testing PSA biomarker samples in solutions containing a complex mixture of blood-derived serum proteins and found that the test could enable reliable diagnosis.

Imperial College London department of materials and bioengineering professor and senior author of the study, Molly Stevens, said it is essential to detect diseases at an early stage as it provides a chance to halt the disease before the symptoms worsen.

"However, for many diseases, using current technology to look for early signs of disease can be like finding the proverbial needle in a haystack," Stevens added.

"Our new test can actually find that needle. We only looked at the biomarker for one disease in this study, but we’re confident that the test can be adapted to identify many other diseases at an early stage."

Further, the team will carry out clinical testing to evaluate the efficacy of the biosensor in detecting a range of different biomarkers associated with conditions such as HIV and other infections.

The research was funded by the European Research Council and through a Marie Curie fellowship.