If the water stays pink this would suggest you have cancer, although the test can not detect what type or how advanced the disease is.
The new method from the University of Queensland looks for differences in the genetic code of cancerous and healthy cells.
When placed in solution, those intense clusters of methyl groups also caused cancer DNA fragments to fold up into three-dimensional nanostructures that really like to stick to gold.
The test hinges on a unique DNA signature that appears to be found in all cancers, discovered by a team of scientists at the University of Queensland's Australian Institute for Bioengineering and Nanotechnology (AIBN).
"We believe that this simple approach would potentially be a better alternative to the current techniques for cancer detection".
He said: "Virtually every piece of cancerous DNA we examined had this highly predictable pattern".
The test has yet to be conducted on humans, and clinical trials are needed before we know for sure if it can be used in the clinic.
It is now hoped the tests, using blood or tissue samples, will be available within ten years.
Previous research has shown that the pattern of DNA methylation in cancer cells differs from that in healthy cells.
This finding directed us to develop a test that can detect cancerous DNA in blood and tissue.
The types of cancers we tested included breast, prostate, bowel and lymphoma.
It is based on a process known as epigenetics - the attachment of a chemical tag known as a methyl group to DNA.
These distinct patterns of molecules control which genes are turned on and off at any given time and "decorate the DNA".
The team noticed that in cancer cells, methyl groups were clustered at certain positions on the genome - a stark contrast to healthy cells where the groups are dispersed throughout. This changes the colour of the solution containing the nanoparticles and this change can be detected with the "naked eye" said Trau. She said, "Our technique could be a screening tool to inform clinicians that a patient may have a cancer, but they would require subsequent tests with other techniques to identify the cancer type and stage".
The testing was developed by researchers at the University of Queensland in Australia.
The researchers acknowledged that their test needs further study, "but it looks really interesting as an incredibly simple "universal marker" of cancer", Trau said in the statement.
"We certainly don't know yet whether it's the holy grail for all cancer diagnostics but it looks really interesting as an incredibly simple universal marker of cancer, and as an accessible and low-cost technology that doesn't require complicated lab-based equipment like DNA sequencing", Professor Trau said.