Fascinating findings of 2024

Electric attraction

When two people meet, some chemistry and a “spark” between them often leads to a deep connection. The same is apparently true for some metals and foods. Chemists found that applying an electric current at the interface between certain metals and various meats, vegetables, and fruits creates bonds that glue together the hard and soft materials (ACS Cent. Sci. 2024, DOI: 10.1021/acscentsci.3c01593). They remained stuck when the researchers turned the current off. Reversing the polarity of the current broke the bonds.

Listening to proteins fold

Sound helps us visualize things we cannot see. Scientists applied this principle to get a unique glimpse into the process of protein folding, which is key to understanding biological function. The researchers assigned a pitch to each hydrogen bond that forms during a simulation of a protein folding into a complex 3D structure. The simulation revealed the various routes—some slower than others—that proteins take on their folding journeys (Proc. Natl. Acad. Sci. U.S.A. 2024, DOI: 10.1073/pnas.2319094121).

Chemicals in plastic food packaging

Plastics contain chemicals. But just how many, and can they harm health? To find out, researchers collected plastic food packaging from five countries and used mass spectrometry to analyze chemicals extracted from the items (Environ. Sci. Technol. 2024, DOI: 10.1021/acs.est.3c08250). One piece of cling film from the UK contained a whopping 9,000-plus compounds. In laboratory tests on cells, extracts from all the samples interacted with cell receptors that play key roles in human endocrine and metabolic systems.

Lasers liberate hydrogen

When made by splitting water using renewable electricity, hydrogen is a valuable green fuel. But it is expensive and tricky to transport. Some companies want to use ammonia as a hydrogen carrier. Releasing that hydrogen typically requires heat, pressure, or catalysts. This year, researchers showed that you could instead zap ammonia-water solutions with brief, intense laser pulses to free the hydrogen (J. Am. Chem. Soc. 2024, DOI: 10.1021/jacs.3c13459). Using solar-pumped lasers for this process would make it energy efficient.

Quartz + quakes = gold

Quartz’s piezoelectricity—its ability to generate voltage under mechanical strain—is the secret behind the formation of gold nuggets in quartz deposits near geological fault zones (Nat. Geosci. 2024, DOI: 10.1038/s41561-024-01514-1). Researchers confirmed this idea by submerging quartz in gold-containing solution and applying strain to simulate a quake. The quartz develops cracks that fill with gold-laced water. It also produces voltage, and the electrons reduce gold ions in the water, thus precipitating solid gold.

Disorder gives blue hues

Many birds and bugs have vibrant colors not because of pigments and colorful compounds but because of the way tiny structures on their bodies reflect light. In this world of so-called structural color, order is usually key. Blue fruits bend that rule, researchers discovered this year. They examined blueberries, plums, and other blue fruits with a scanning electron microscope and found that the fruits’ distinct hue, in fact, arises from the disordered structure of their waxy outer coating (Sci. Adv. 2024, DOI: 10.1126/sciadv.adk4219).

Cryptic brain preservation

Brains usually dissolve within days after death. Depending on environmental conditions, though, five processes can preserve brains for hundreds or even thousands of years, researchers concluded after analyzing records of over 4,400 brain fossils (Proc. R. Soc. B 2024, DOI: 10.1098/rspb.2023.2606). Freezing, tanning, dehydrating, and saponifying all do the trick. A fifth, cryptic, method preserved brains for as long as 12,000 years. The team’s theory is that, catalyzed by iron, proteins and lipids in the brain cross-link to form stable molecules.

Body battery

Our bodies are chock-full of reactive chemicals and ions. Why not use them to power medical implants and wearables? That was the thinking of researchers who created a metal-oxygen battery that uses the body’s oxygen as a continuous energy source (Chem 2024, DOI: 10.1016/j.chempr.2024.02.012). The proof-of-concept device uses a sodium-based anode and a nanoporous gold cathode. But in the future, this type of battery could use sodium ions found in the body.