Detection of rare metals used in smartphones made easier with innovative sensor

Research shows lanthanide based bacteria to be fluorescent indicators

A new protein-based sensor could help in better detection of lanthanides, the rare metals used mainly in all smartphones. Research has revealed a technology to allow for fluorescence when this protein binds to the metals. Pennsylvania State University's research team had used it to explore the biology of bacteria that use lanthanides.

"Lanthanides are used in a variety of current technologies, including the screens and electronics of smartphones, batteries of electric cars, satellites, and lasers," said Joseph Cotruvo, Jr., Assistant Professor and Louis Martarano Career Development Professor of Chemistry at Penn State and senior author of the study.

The team also determined that the bacteria take in lanthanides much like many bacterias take in iron; they secrete small molecules that tightly bind to the metal, and the entire complex is taken into the cell. This reveals that there are small molecules that likely bind to lanthanides even more tightly than the highly selective sensor.

The study appears in the Journal of the American Chemical Society. The research team re-engineered a fluorescent sensor used to detect calcium, substituting the part of the sensor that binds to calcium with a protein they recently discovered that is several million times better at binding to lanthanides than other metals. The protein undergoes a shape change when it binds to lanthanides, which is key for the sensor's fluorescence to "turn on."

A new field called the development of sustainable smartphones is expected to boom substantially in future.

Your smartphone is a bundle of metal gems

Smartphones are pocket-sized vaults of precious metals and rare earth. A typical iPhone is estimated to house around 0.034g of gold, 0.34g of silver, 0.015g of palladium and less than one-thousandth of a gram of platinum. It also contains the less valuable but still significant aluminium (25g) and copper (around 15g).

The research team re-engineered a fluorescent sensor used to detect calcium, substituting the part of the sensor that binds to calcium with a protein they recently discovered that is several million times better at binding to lanthanides than other metals. The protein undergoes a shape change when it binds to lanthanides, which is key for the sensor's fluorescence to "turn on."

Smartphone addiction is worse than you think!

According to the Minerals Education Coalition, a baby born in the US today will use up 539 lbs of zinc, 903 lbs of lead and 985 lbs of copper during his or her lifetime, not just in phones but in other gadgets and appliances too. In terms of environmental drain from every smartphone that's made, you can add the oil used to produce plastics, the sand used to produce glass, and so on.