精东视频

You could call it a light-bulb moment. In 2006, Professor Kate Jolliffe鈥檚 colleague happened to glance at a whiteboard over her shoulder. The molecule she had drawn looks like it could interact with cell membranes, he suggested.

It took a decade of hard work, but Jolliffe has turned this spark into a molecular 鈥榣ight bulb鈥� that can .

鈥淚t can be used in any application where researchers want to see if cells are dying,鈥� says Jolliffe, 鈥渇or example to monitor whether a cancer drug is having the desired effect and killing the cancer cells.鈥�

How to switch on a molecular 鈥榣ight bulb鈥�

The 鈥榣ight bulb鈥� can pinpoint dying cells by spotting phosphatidylserine on the outer surface of the cell membrane. In healthy cells, it is a building block of the membrane鈥檚 inner layer. A cell displaying phosphatidylserine on its surface is like waving a white flag鈥�.

Jolliffe鈥檚 molecular light bulb consists of three components:

• a slot for phosphatidylserine
• a fluorescent dye molecule
• a hook to anchor the sensor to the cell membrane.

absorb one colour (wavelength) of light and emit a different colour. We can鈥檛 see the UV light that glow-in-the-dark paints absorb, but we can see the visible light they emit. That鈥檚 fluorescence!

Jolliffe鈥檚 light bulb only 鈥榮witches on鈥� when it scoops up phosphatidylserine. To do this, it must adjust its hold on the dye molecule. Freed from its restraints, the dye molecule can fluoresce. Scientists can simply check their cells under a microscope to see if any light up.

Picking out anions from chemical soups

The light bulb is one in a series of molecular architectures designed by Jolliffe using the 鈥榯oolbox of organic chemistry鈥�. Many of them are built for detecting anions: , giving them a negative charge.

鈥淭he species that we look at, anions, are present everywhere. They're in industry, they're in the environment, and they're in biology,鈥� she says.

They鈥檙e in our waterways. Measuring nitrates and phosphates helps us monitor the health of the ecosystem. While both the elements nitrogen and phosphorus are important for the environment, too much of either can result in algal blooms with potentially disastrous consequences.

They鈥檙e also in our blood. Chloride is an important electrolyte, and  can be used to help diagnose serious conditions like high blood pressure, liver disease or even heart failure.

Natural environments and biological fluids are both complex chemical soups. Designing a molecular structure to capture a specific anion isn鈥檛 enough鈥擩olliffe鈥檚 structures also need to have a strategy in place to deal with interference from other anions.

It鈥檚 a tough problem to solve鈥攏ot just for Jolliffe, but for all chemists. 鈥淭rying to design a system that will bind to a specific anion in water, for example, is still something that we鈥檙e really not very good at doing,鈥� she says.

But the journey is filled with delight. 鈥淥ne of the beauties of chemistry and synthetic chemistry is the ability to create a molecular structure that nobody's ever made before, which is kind of neat,鈥� says Jolliffe.

Chemistry beyond the molecule

Chemists generally study single molecules. Supramolecular chemists like Jolliffe are more interested in the interactions between two or more different kinds of molecule. It鈥檚 the 鈥渃hemistry beyond the molecule鈥�, as 1987 chemistry (PDF, 4.6 MB).

Studying these interactions teaches chemists how molecules could be coaxed into forming complex structures spontaneously, with little interference from the chemists themselves. This is called self-assembly.

It鈥檚 a process mastered by the most sophisticated chemist of all: nature. Essentially, all biological organisms鈥攊ncluding you鈥攁re just a very complex assembly of molecules.

鈥淪upramolecular chemists effectively try to make small, simple systems that mimic the functions of nature鈥檚 complex machinery,鈥� says Jolliffe.

And the chemists are getting better at it. The 2016 Nobel Prize in Chemistry was awarded to supramolecular chemists who created the .

Jolliffe was recently elected a Fellow of the 精东视频 in recognition of her contributions to 精东视频.