How do Scientists Study Complex Chemical Systems?

Much of our work in the Center for Sustainable Nanotechnology lies in the realm of chemistry. That is to say, our work seeks to understand phenomena at the molecular level. For example, we want to know what molecules we can add to the surface of a nanoparticle to control how stable it is and how it interacts with cells. But how exactly do we tackle problems in chemistry?

To address molecular-level questions like these, we conduct experiments using instruments that can probe the characteristics of molecules. Molecules are the smallest units of most chemicals—many being smaller than the nano-scale, around 1 billionth of a meter. Some instruments that we use provide direct information about molecules, like how they rotate, vibrate, absorb and emit energy. Other instruments that we use don’t necessarily provide direct information about molecules, but they allow us to visualize things much closer to the scale of molecules than we otherwise can.

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Happy Mole Day from the CSN!

co-authors: Mimi Hang & Marco Torelli

The word mole is one of those crazy words that have multiple meanings that can sometimes lead to confusion.  Perhaps your first thought after hearing the word is a cute little animal that burrows in the ground.  Or maybe your mind jumps to the small growths on your chin.  Or if it’s food you’re into, the delicious sauce you put on your enchiladas may be the first thing that you think of.  But for us scientists, a mole is actually a unit of measure that we use daily. And today just happens to be the most important day for the mole – Mole Day!  Yahooooooo!  It’s a day celebrated every year on October 23rd from 6:02 a.m. until 6:02 p.m. Seems pretty specific, right?  Well, let’s explore what this unit actually is…

a happy mole

Happy Mole Day! image source

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Nobel 2014: What makes super-resolution microscopy so super?

The awarding of the 2014 Nobel Prize in Chemistry to Dr.s Betzig, Hell, and Moerner (my former research mentor) is a tremendous event! It is almost as tremendous as their scientific targets are tiny: they were awarded the prize for super-resolution fluorescence microscopy, a technique for using a light microscope to examine objects as small as tens of nanometers. Dr. Christy Haynes talked about super-resolution microscopy in a recent blog post, so I won’t cover that again here. However, one of the enabling technologies for this year’s prize is the ability to use light to “see” individual molecules. Professor Moerner is a pioneer in what has come to be called “single molecule spectroscopy.” He is a true single-molecule zealot, and as a former trainee in his lab, I’m pretty much a single-molecule zealot as well. In this post, I hope to convince you that studying individual molecules is worth being zealous about.

Nobel Medal awarded to Normal Angell in 1933

Nobel Medal awarded to Normal Angell in 1933.              image source

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Teeny Tiny Motors That Fit in Your Body

Imagine tiny gadgets wandering around in your bloodstream, travelling into your cells to seek out infections and fight diseases… Does it sound too fantastic to be true? Let’s explore just how close this science fiction scenario is to a reality.

1 - robot in red blood cells

Before we get too far into this story, let’s first see where the idea of really, really small motors comes from. In 1954, the gifted physicist Richard Feynman issued a $1,000 challenge in his speech at Caltech.1 He offered a big prize to the first person able to create an operating electrical motor smaller than 1/64 inch (about 50 times smaller than a pocket-size flash drive!). Scaling it down was a great challenge since the effect of shrinking the size on the operation of the motor was unpredictable.  But to Feynman’s surprise, shortly after the speech, an electrical engineer built the world’s smallest hand-made machine at the time. The challenge-winning motor, while not quite on the nano-scale, undoubtedly inspired scientists and triggered research on future applications of very small, functioning motors. Continue reading

Bright Nanoparticles + Glowing Bacteria = Beautiful, Useful Pictures

One major type of output from university research labs is the publication of scientific results in scientific journals. When we write these papers, our target audience is not the general public; rather, we are writing for experts in our area to tell them what we’ve accomplished so that they can build on our work in their own continuing research. These journal articles are an often-used measure of a university professor or graduate student’s success – people track how many scientific journal articles they’ve published and how many people have cited their papers in ongoing work. From the perspective of the general public, however, scientific journal articles can be difficult to read and digest. That said, they are critical to keep the scientific enterprise moving forward. If everyone kept their experimental results to themselves, much time and money would be wasted as many laboratories unknowingly pursued the same experiments.

Two of the scientists in our center using a microscope at the Pacific Northwest National Laboratory.

Two of the scientists in our center using a microscope at the Pacific Northwest National Laboratory.

In hopes of making a recent Center for Sustainable Nanotechnology paper more relevant to the general public, I’m going to spend this blog post describing recent work and explaining why it’s important. Recently, some of the researchers in our center published a paper titled, “Facile Method to Stain the Bacterial Cell Surface for Super-Resolution Fluorescence Microscopy” in a journal known as Analyst. The title alone can be quite intimidating but, put simply, this paper describes a way that researchers in our center have been able to visualize bacterial cells more clearly than can be done with any standard light microscopes. Continue reading

Not Your Daddy’s Sunblock – Why Thick, White Sunblock is a Thing of the Past

Not Your Daddy’s Sunblock – Why Thick, White Sunblock is a Thing of the Past

As a child, I spent many summer days at the beach in southern California. I remember playing in the surf, collecting shells, watching sea lions, and seeing the white noses of the lifeguards. In those days, lifeguards smeared thick, white zinc oxide paste on their noses to protect themselves from getting sunburned


My nose, smeared in Zinka Sunblock, which contains zinc oxide particles

When my kids were young there was a brief period when colored zinc oxide sunblock seemed to be in vogue


My nose, smeared in colored Zinka Sunblock

Nowadays, we still use zinc oxide in sunblocks, but it’s no longer white or colored; it’s transparent! How can this be? It’s the same material!!

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Nano-Sensors: Small size, big impact

If you took high school chemistry, you might remember using pH indicator strips. You’d take a piece of the specially treated paper, dip it in your solution, and watch it change color depending on whether you had an acid or base.

At the time, you might have been more excited by the fact that the paper changed color than about what you were accomplishing with the task. However, chemical sensors aren’t just visually appealing—they also play an important role in monitoring conditions both inside and outside of the lab. Continue reading