Integrating into a smartphone, a hand-held device capable of detecting and quantifying the concentration of prostate-specific antigen (PSA) in a blood serum sample has recently been developed by researchers at McMaster and Brock universities, Canada. Termed an electrochemical bio-barcode assay, the device could be modified to detect a variety of biomarkers, including markers of malignancy, at home or in a primary care setting.
To receive results in a matter of minutes, the user mixes a few drops of their blood with a small volume of liquid reagent, which is then added to a strip and inserted into a reader, much like how diabetic patients monitor their glucose levels at home. This point-of-care approach allows for immediate results which can then inform management plans, ultimately giving the patient access to the appropriate treatment at a faster rate. Although still in its preliminary stages, this technology could mark a departure from more invasive sampling that requires laboratory processing, potentially taking days or weeks before a result is available.
“This is another step toward truly personalised medicine,” says Leyla Soleymani, a researcher involved in the study. “We’re getting away from centralised, lab-based equipment for this kind of testing. This would make monitoring much more accessible and cut down on the number of times patients need to leave home to provide blood samples.”
Despite a simplistic, user-friendly design, detection involves DNA/antibody complexes which react with the target biomarkers, the binding of which releases a by-product that can be detected by the device. This avoids multi-step laboratory assays that require time and big, expensive equipment, with the added advantage of being compatible with unprocessed human plasma samples.
Although this is just a ‘proof-of-concept’, it is hoped that with modification, other biomarkers will also become detectable. Researchers plan on further testing before applying for regulatory approval and commercialisation.
“Once commercialised, this device will be a paradigm shift for cancer diagnosis and prognosis,” says Feng Li, another researcher involved in the project. “Since this device is a lot more accessible and user-friendly than conventional technologies, patients will be more willing to use it, which can improve clinical outcomes and save lives.”
Currently, Belgium has national screening programmes in place for cervical, breast and colorectal cancer. All of these programmes could benefit from a cost-effective, point-of-care test that has the potential to increase screening uptake, due to the simplistic and non-invasive nature of the tests. In addition, cancer screening programmes previously unfeasible due to cost-effectiveness could potentially become viable with this innovative ‘sample-in, answer-out’ approach.
Traynor. S M et al., Dynamic Bio-Barcode Assay Enables Electrochemical Detection of a Cancer Biomarker in Undiluted Human Plasma: A sample-in-Answer-Out Approach. Angewandte Chemie2020.