New enzyme biomarker test indicates diseases and bacterial contamination

Researchers from Queen's University in Belfast have come up with a novel, innovative enzyme biomarker test that can indicate disease and bacterial contamination, thus saving time, money, and time. money and possibly life.

The test, developed by scientists at the Institute for World Food Security at Queen's, allows for the detection of enzymatic markers of the disease, known as proteases, in humans , animals and food products.

Proteases are essential for the growth of microorganisms and are responsible for the progression of many diseases.

Protease levels can be very high in the urine of patients with diabetic nephropathy or at sites of infected wounds. Similarly, in cows, an elevation of proteases in their milk may reveal diseases such as bovine mastitis, a type of infection of the mammary glands. In foods, proteases produced by contaminated bacteria in meat and dairy products can lead to rancidity, as well as reduced shelf life and quality.

Current protease detection methods are expensive, time consuming and not always effective. Scientists at the Queen 's Institute for Global Food Security have developed a nanosensor that has enabled sensitive, rapid and cost – effective detection of proteases in milk and urine.

Dr. Claire McVey, researcher at Queen's and co-author of the study published in a prominent journal Nano Researchexplains: "Not only is the test inexpensive to produce, but it can be used anywhere and does not depend on laboratory conditions. Eliminating the need for laboratory testing is a life change. In addition to being profitable, it means faster diagnosis. "

The nanoparticle-based nanosensor designed by Queen's researchers indicates when proteases are present during a visible color-change reaction. Gold nanoparticles are well known for their ability to accelerate the oxidation of a chemical called tetramethylbenzidine (TMB), visible by bright blue formation.

When casein (a molecule present in milk) is added to gold nanoparticles, it surrounds the nanoparticles and serves as a protective surface barrier. When TMB is introduced, casein prevents the oxidation reaction, which means that there is little or no change in color.

Where proteases are present, they "eat" the protective barrier of casein, exposing the surface of the gold nanoparticles. In this case, when TMB is added, the proteases removed the casein, which means that the oxidation occurs rapidly, resulting in a rapid change of color.

Dr. Cuong Cao, the lead academic of the study: "When we add TMB to gold nanoparticles coated with casein, we can instantly determine whether proteases are present, whether the solution turns blue or not. Normally, such tests take a lot longer. "

Using this approach, proteases can be detected in 90 minutes without the use of complicated or expensive laboratory equipment.

In addition, the "ingredients" necessary to manufacture the nanosensor are readily available and inexpensive. Gold nanoparticles can be produced in abundance, with few restrictions on storage requirements, making it a durable and inexpensive substance.

The approach developed by Queen's researchers has been tested on milk and urine, but it could be adapted to a number of other applications.

Dr. Cao explains: "The use of molecules other than casein to coat the surface can detect other types of enzymatic biomarkers, for example, covering lipid nanoparticles could detect the enzyme." lipase, which could help in the diagnosis of diseases such as pancreatitis.

"After the full validation of this test, we would like to explore ways to extend the application to the detection of other diseases or contaminated foods.This new approach will identify enzymatic biomarkers on the place of treatment, how enzymatic biomarkers are detected and diagnosed, which has an impact not only on food safety, but also on the diagnosis of enzyme-related diseases in animals and humans. possibilities of this essay are enormous. "

Professor Elliott, founder of the Institute for Global Food Security and co-investigator of the study, commented, "The ability to quickly diagnose a disease or a contamination can have a huge impact on how people serious problems can be addressed, the system will help reduce test costs and could transform the number of tests in developing countries. "