Long-time chemist Allen Bard doesn’t aspire to become a household name; he cares more about mentoring young scientists. But fame has found him anyway—some scientists might know him as the father of modern electrochemistry.
A half-century ago, Bard pioneered research in electrogenerated chemiluminescence (also called electrochemiluminescence), a process that harnesses the energetic transfer of electrons between molecules to create light. Known as ECL, the technique has become part of a standard clinical assay to identify a range of microscopic substances, from proteins to viruses such as HIV.
Bard, who's a professor at the University of Texas and runs its Center for Electrochemistry, was also among the first scientists to experiment with photoelectrochemistry, which involves producing electricity or chemicals from light—research that he still pursues.
Credit generally goes to Bard as well for developing a novel imaging technique called scanning electrochemical microscopy, which scientists use to study electrochemical behavior—that is, the flow of electrons to molecules, atoms, and other chemical species—at the interface between a liquid and solid or a biological cell.
Formerly the editor-in-chief of the Journal of the American Chemical Society, Bard has, in recent years, received two prestigious honors from President Obama—the National Medal of Science, as well as the Enrico Fermi Award.
Now 80, Bard, along with his team of students and postdoctoral researchers, is researching a material that could serve as an alternative energy source by helping carry out artificial photosynthesis.
Science Friday asked Bard about his early interest in science, his approach to research, and his proudest achievement.
Science Friday: At what point did you know you wanted to be a scientist?
Allen Bard: I knew at a very early age. My brother was 11 years older than I, and my sister 10, and they both encouraged me in science. They both had chemistry sets and took me to the American Museum of Natural History in New York, which had movies about scientists, such as the story of Louis Pasteur, and all kinds of things.
What field of science were you initially interested in, and did that change when you got older?
I was interested in biology and animals, which I think most kids are. That continued even through high school, but at that time I didn’t see biology as a very advancing field—this was pre-molecular biology, pre-DNA. So I decided chemistry was really better for me.
Did you have a scientific idol?
As a youth, the one who most interested me was Luther Burbank. It was fascinating to me that he could mix up two fruits just by doing a graft. Later on, I suppose it was Linus Pauling. I thought he was a very interesting guy.
Do you always have a practical use in mind when doing research?
It depends. When I was doing the initial work in ECL, or electrochemiluminescence, I didn’t have a particular practical use or goal in mind. I was doing it because I was really curious about how things were happening and understanding them. But then at a certain stage, when you work on something, you start to see possible applications.
We tried, in the beginning, to make a laser with ECL, which never worked. Much later, we got the idea of using it as a clinical test. In a lot of these clinical tests, where you’re looking for proteins or viruses or something, you have an antibody that will stick to that particular substance—‘I’m looking for X; I can get an antibody that will hit and stick to X.’ But to know when that happens, you have to put a label onto that antibody—something that you can detect analytically. It might be fluorescence, it might be radioactivity, or it might be electrochemiluminescence. With George Whitesides, who is an organic chemist who knew more about immunochemistry, we worked out a clinical assay using ECL that basically is the standard assay right now for doing clinical analysis. So in that case, it ended up being more successful and useful than I ever would have imagined.
On the other hand, things that I thought would be very useful, like our early stages of photoelectrochemistry—taking light and doing chemistry with it—haven’t panned out yet. We had a nice technique for taking a semiconductor material—an inexpensive one like titanium dioxide—throwing it into polluted water, shining sunlight on it, and cleaning up the water. And I thought that was going to be a very useful thing, but it just wasn’t competitive with less expensive methods.
How did you become interested in photoelectrochemistry?
In the early ’70s, I gave a lecture at the University of Wisconsin on electrochemiluminescence, and somebody in the audience raised their hand and said, ‘You know, it’s easy to take electricity and make light—we do that all the time. What you really want to think about is using light to make electricity using solar energy.’ And it turned out that the guy who asked that question was Farrington Daniels, who was quite a well-known physical chemist and had been interested in solar energy for some time. It took a few years for me to start understanding how one might generate electricity with light through electrochemistry, and then serendipitously, there was the first energy crisis around 1973. People all of a sudden got really worried about oil and coal running out, and climate change was on the horizon, and so people started working seriously on solar energy—President Carter pushed for it. So I guess, luckily, I got into the field at the right time.
What are you currently working on?
We’re working on several things, but I think the most interesting in terms of practicality is, we’ve embarked on trying to make inexpensive thin silicon to perhaps fabricate a solar cell. Right now we believe silicon is the most advanced material—it’s been investigated very thoroughly by a lot of people—but it’s been impossible to get the price down. Silicon is difficult to make, and for it to be useful in a solar cell, it has to be very pure—something like 99.99999 percent pure.
What do you think you would have done if you hadn’t gone into science?
There were a lot of things I liked, but I couldn’t do. I liked music. I liked art—I liked to draw and paint. But I knew I couldn’t do any of those well enough to think about it as my life’s work. Really, I never gave it a lot of thought. Science was going to be it for me.
Outside of scientific literature, what do you read?
I’ve been reading books that I missed when I was growing up, mostly. I don’t read much modern fiction. But I’ve gone back and started looking at older books, for example, Brave New World. I tend to pick an author and then read a lot of the stuff that he’s done. I’ve been going back over a lot of (George) Orwell stuff—1984, Animal Farm, Keep the Aspidistra Flying. I’ve gone back and read a lot of (Charles) Dickens.
What professional accomplishment are you most proud of?
I think I’m most proud of the people I turned out. I don’t know if you consider that a professional accomplishment. But you think about scientists who were famous when I was young and who were my idols when I was in graduate school—they are not known by my students, at all. They don’t even know the names. It’s very hard in science to make such an important contribution that you become a household name and your ideas go into textbooks. Ultimately, I think everybody has to realize that we all work on this because we like it and because we understand that we’re building a structure. And we each put in a little brick here and there, and if everybody puts in the right bricks and everybody works hard at it, you build a big structure of science, and it’s not so important who put the bricks in.
As I tell my students, it’s not only doing science that’s so much fun, which it is, and so challenging, and so stimulating, but it’s that you also become a member of a moderately exclusive group of people who are all interested in the same kinds of things you are—they’re maybe a little nerdy, but they’re all interested in the kinds of things you get excited about, so you can sit down and instantly talk with them and get on the same wavelength, independent of where they’re from or what country or so on.
Do you think about retiring?
Well, I’ll retire when I have to retire, because there is nothing I like to do better than what I do. I love doing science, and the challenge of it, and working with new people and young people. I’ll do it as long as I can.
This interview has been edited for space and clarity.