By Michelle Mukonyora
10 February 2016
Black spots on a banana peel are usually a sign of an overripe banana, and scientists may have found a novel way of indirectly using this feature in detecting the growth stages of melanoma, which is a form of skin cancer. The brown spots on a banana peel are caused by the enzyme tyrosinase. Tyrosinase is also present in the human skin and is over-expressed in patients with melanoma (Figure 1). During stage one melanoma, the spots are few and sparse. Stage two is characterised by widespread and evenly distributed spots. With the final stage three, the spots are uneven and are beginning to spread on the body.
Researchers at the Laboratory of Physical and Analytical Electrochemistry in Switzerland have developed a scanner with eight microelectrodes that when passed over the skin, measures the amount and distribution of tyrosinase (Figure 2). This device was initially tested on banana peels. The advantage of such a device is that it may reduce the need to carry out biopsies and it may also be used as a tool to destroy melanoma cells. Detecting melanoma early during stage one increases the survival rate of this lethal cancer to 95% for ten years. Diagnosis at stage three sees the survival rate drop to 43%.
This research was published in the science journal “Angewandte Chemie”.