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Professor Joseph Wang of the University of California San Diego (UCSD), USA, is the first to be awarded the IUPAC Analytical Chemistry Medal—an award that recognizes a significant lifetime contribution to analytical chemistry and for researchers who have a substantial record of achievements demonstrated by the number and quality of their publications, by being actively involved in international partnerships as well as by their commitment in the training of the next generation of analytical chemists.
Here he speaks with Dr. Vera Koester of ChemistryViews about his current research, especially the exciting development of wearables, and giants in chemistry.
What does it mean to you to receive the IUPAC Analytical Chemistry Medal and to be the first to receive it?
It has been a great surprise and is a great honor. I have received numerous international awards, and this is a kind of global recognition. In analytical chemistry we don’t have a global award, which makes this very prestigious.
You started your research career in analytical chemistry but have since done pioneering work in many areas. How come?
Yes, I work in many fields. I started out in analytical chemistry. For twenty years I was involved in chemistry, and then later in nanoengineering.
I like to move on to new topics. I can identify problems very quickly, use my knowledge from analytical chemistry, and combine things towards innovative solutions.
How do you identify your research topics?
When I go to a conference, I usually not focus on analytical talks. I try to learn completely new things from different disciplines, to adapt them, and see how my basic knowledge can be useful in this regard.
Some scientists make very intricate, complicated things, but I try to find simple solutions that address major societal needs.
You and your team, for example, just developed a device that converts the chemical and mechanical energy from the surface of our fingertips into electrical energy to power wearable electronics such as electrolyte sensors or drug detectors. Can you say something about this work?
The wearables field is amazing. I mean, the Apple Watch already has an ECG (electrocardiogram), and I can measure my steps all the time with a smartphone. This is truly real-time measuring of our mobility. But everybody dreams of doing non-invasive continuous chemical sensing. For glucose, it already exists because the diabetic market is so big. The devices used to be quite large in size in the ’70s, then came disposable strips for blood glucose measurement for diabetics in the ’90s, and now the glucose meter is worn directly on the body.
So moving from the large laboratory to mobile devices is possible, and now we have moved to devices worn on the body—to continuous flexible devices, in other words. This can be in the mouth or on the skin or even in the eyes, like contact lenses. It’s amazing how these things have evolved. There was no such thing as a wearable sensor like this until ten years ago.
We pioneered the development of sensors on the body for measuring chemical metabolites like glucose, lactate, or electrolytes. This is now the subject of flexible bioelectronics. We use thesewearable electrochemical devices not only for measurement but also for energy application on the body. In a recent major paper, we’re extracting energy from sweat of the fingertip, as you said.
Previously, it required exercise to generate energy. Now we are finding that in the fingertip alone you have a lot of perspiration. So now you can go to sleep and still get your sweat to transform into energy [1, 2].
We recently published an interesting paper published last month in Angewandte Chemie on monitoring a patient with Parkinson’s Disease using a strip via naturally secreted fingertip sweat [3]. Here we are presenting the first example of individualized therapeutic drug monitoring after taking a standard oral L-dopa pill. The monitoring is based on dynamic tracking of the drug concentration in the naturally secreted sweat of the fingertips.
This represents the first example of this technology using sweat. If patients are shaking, you need a quick response to adjust the dosage of the L-dopa. But at the moment they have to send the blood to the lab and then wait for one week to get the analysis.
We are also working on microneedles. We call it a “lab under the skin.” I can have different needles for different biomarkers. So in a 1 cm² area, I can put 16 microneedles, each one for a different biomarker. The beauty of the microneedles is that you can really measure continuously multiple biomarkers.
Do you have other recent examples of monitoring more than one parameter at the same time?
One example of the crazy ideas we have had is the blood pressure chemical monitoring (BPCN) tattoo. It combines chemistry and blood pressure in the same tattoo.
It’s a non-invasive device worn on the skin to simultaneously monitor blood pressure and heart rate via ultrasound transducers and multiple biomarkers via electrochemical sensors. Glucose, lactate, caffeine, and alcohol are measured in sweat. The device is elastic and conforms to the surface of the skin. It allows one to monitor the physiological effects of food intake and physical activity. [4]
Another example of recent research is a self-stirring pill. Instead of taking just the drug orally, we put a motor (acting as tiny stirrer) into the pill itself, which speeds up dissolution of the pill and greatly improves the bioavailability of the drug. So when the pill is dissolved in the stomach, it’s really pushing the drug into the mucosa, and then it gets into the blood faster. We have demonstrated this for aspirin, acetaminophen, and dopa. Aspirin, for instance, needs to get into the blood quickly in a cardiac emergency. [5]
And there are always new problems to solve. We recently published an article in JACS about a micromotor that captures and removes coronavirus from contaminated water. Coronavirus can survive in water for several days and poses a potential risk for waterborne transmission to humans. An algae-based microrobot was made using click chemistry. The microalgae were functionalized with angiotensin-converting enzyme-2 (ACE2) receptor against SARS-CoV-2 spike protein. This ACE2 algal robot has fast and long-lasting self-propulsion in various water media, so you do not need extra fuel. [6]
What are current trends in the field of sensors?
There is this trend of moving away from the big laboratory to smaller and smaller home testing and towards the body: the lab on the skin or in the mouth. That’s true for all techniques. This field began benefitting from nanotechnology 10 to 20 years ago.
I’m glad to be part of this revolution of moving to home testing and towards real-time on-body testing.
So do you think in 50 years’ time we will measure everything that we are doing right away?
Oh, yes, in 50 years for sure.
The future will bring increasingly smaller sensors. So at some point you will have a complete lab under your skin. You will swallow a lab in a capsule—namely swallow a small capsule that will then analyze your gut. In fact, you will see that within 10 years. We don’t have to wait 40 or 50 years for that.
Sounds amazing but also scary. You have access to so many sensors, what do you monitor on yourself?
Oh, mainly my steps and sometimes my blood pressure.
Are you involved in IUPAC?
I have been involved in several IUPAC projects and have written a lot of IUPAC reports. For example, I was a member of the commission for analytical chemistry, defining exactly different sensing devices and techniques.
What do you like most about IUPAC and what do you think could be different?
IUPAC is responsible for somehow standardizing everything. That is very good. Even in electrochemistry, we have different nomenclatures. Sometimes we use different names for the same techniques or present results in different ways. There was also a lot of confusion in the beginning about what exactly a biosensor is. In my opinion, they did a good job in defining it.
It’s also extremely important to take a global perspective. In materials, we have MRS as the global conference for material science; Pittcon is the biggest international conference in analytical chemistry. IUPAC needs to have more visibility. I would like to see IUPAC take a leading role in the top sciences. Merging IUPAC’s analytical topics and sessions with Pittcon would mean more visibility for analytical chemistry.
If you could have coffee with a great historical or living chemist, who would that be?
There are a lot of giants in analytical chemistry, like Izaak Maurits Kolthoff (1894–1993; he is widely considered the father of analytical chemistry). But there are also legends who are still alive. George Whitesides is 82 years old and still creative. He pioneered soft lithography and also moves onto new fields every five to ten years.
Beyond analytical chemists, Robert Langer in MIT is doing an amazing job. He is a pioneer of many new technologies, including controlled release systems and transdermal delivery systems that allow drugs to be administered or analytes to be extracted from the body through the skin without needles or other invasive methods.
So there are a lot of smart, amazing people out there, and I’m fortunate to have lived long enough to have known many of them who are no longer with us. Like Willy Simon (Wilhelm Simon 1929–1992), who worked at ETH Zurich, Switzerland, and pioneered the field of iron-selective electrodes. He passed away relatively young; he was only 62 years old.
Another giant is Ralph Adams (1924–2002) of the University of Kansas, USA. He pioneered the introduction of electrodes into the brain in the 1970s. He was a visionary character. Brain electrochemistry is a huge topic now, but he had the vision to put this tiny carbon cast electrode into the brain and measure the electrical signal transmission. Coupled with his unique personality, he would be another one to have coffee with.
Often creative scientists have unique characters and are ready to take big steps (instead of incremental ones), achieve something big and make a big impact. All of these major advances rely on basic science, and lots of great electrochemists have done amazing fundamental work characterizing electrode reactions and laying the foundations for all the exciting applications that we are doing these days. That’s the key to everything.
What are you doing in your spare time?
I try to enjoy life with friends. Before the pandemic, a good part of my life consisted of enjoying meeting a lot of friends and colleagues. I like to meet with my former students too. At least every two years we have a meeting.
I work too long, nine days a week, but I still find time to go for a walk and stay in good shape. I like to walk on the beach. I live in beautiful San Diego; the beach is only a 10-minute walk from my office. On Saturday mornings I walk with my wife along La Jolla Shores, which has beautiful beaches.
San Diego is such a beautiful place, even our campus. When I come to campus early, I start with a walk at seven in the morning. If it’s a nice morning and the weather is good, I do my 4,000 steps before I go into the office.
Thank you for the interview.
Joseph Wang, born 1948, studied chemistry at the Technion – Israel Institute of Technology, Haifa, Israel. After completing his D.Sc. in 1978, he served as a postdoctoral research associate at the University of Wisconsin, Madison, WI, USA. In 1980, he joined the Department of Chemistry and Biochemistry at New Mexico State University (NMSU), Las Cruces, NM, USA, where he became a Regents Professor and holder of the Manasse Chair between 2001 and 2004. Between 2004 and 2008, he served as the Director of the Center for Bioelectronics and Biosensors and as a Professor of Chemical Engineering and Chemistry at Arizona State University, Tempe, AZ, USA. Between 2014 and 2019, he served as Chair of the UCSD Nanoengineering Department.
Currently, Joseph Wang is a Distinguished Professor of Nanoengineering and SAIC Endowed Chair at the University of California San Diego (UCSD) and serves as the Director of the UCSD Center of Wearable Sensors at the University of California San Diego Jacobs School of Engineering.
Wang has received numerous international awards, including the Talanta Medal in 2021 and the Bruno Breyer Medal of the Royal Australian Chemical Institute in 2012, honorary doctorates, and professorships. In 1988, he founded the journal Electroanalysis and was its editor-in-chief for three decades until 2018. He has also been a key contributor to the IUPAC project “Electrochemical DNA-based biosensors: terms and methodology” [7].
His research interests include the development of electrochemical biosensors, nanomotors and nanorobots, wearable sensors, flexible stretchable materials, biomedical applications of nanomachines, printable devices, nanomaterials-based sensors, bioelectronics, biorecognition and clinical diagnostics, microfluidic (“Lab-on-Chip”) devices, microfabrication, biofuel cells, new interfaces for electroanalysis and electrocatalysis, sensor/recognition coatings, and remote environmental and security sensing.
References
[1] Lu Yin, Jong-Min Moon, Juliane R. Sempionatto, Muyang Lin, Mengzhu Cao, Alexander Trifonov, Fangyu Zhang, Zhiyuan Lou, Jae-Min Jeong, Sang-Jin Lee, Sheng Xu, and Joseph Wang, A passive perspiration biofuel cell: High energy return on investment, Joule 2021, 5, 1–17. https://doi.org/10.1016/j.joule.2021.06.004
[2] Roswitha Harrer, Energy at Your Fingertips: Transforming Sweat Lactate into Power, ChemistryViews 2021. https://doi.org/10.1002/chemv.202100073
[3] Jong-Min Moon, Hazhir Teymourian, Ernesto De la Paz, Juliane R. Sempionatto, Kuldeep Mahato, Thitaporn Sonsa-ard, Nickey Huang, Katherine Longardner, Irene Litvan, Joseph Wang, Non-Invasive Sweat-Based Tracking of L-Dopa Pharmacokinetic Profiles Following an Oral Tablet Administration, Angew. Chem. Int. Ed. 2021. https://doi.org/10.1002/anie.202106674
[4] Juliane R. Sempionatto, Muyang Lin, Lu Yin, Ernesto De la paz, Kexin Pei, Thitaporn Sonsa-ard, Andre N. de Loyola Silva, Ahmed A. Khorshed, Fangyu Zhang, Nicholas Tostado, Sheng Xu, Joseph Wang, Epidermal patch for the simultaneous monitoring of haemodynamic and metabolic biomarkers, Nat. Biomed. Eng. 2021, 5, 737–748. https://doi.org/10.1038/s41551-021-00685-1
[5] Rodolfo Mundaca-Uribe, Emil Karshalev, Berta Esteban-Fernández de Ávila, Xiaoli Wei, Bryan Nguyen, Irene Litvan, Ronnie H. Fang, Liangfang Zhang, Joseph Wang, A Microstirring Pill Enhances Bioavailability of Orally Administered Drugs, Adv. Sci. 2021. https://doi.org/10.1002/advs.202100389
[6] Fangyu Zhang, Zhengxing Li, Lu Yin, Qiangzhe Zhang, Nelly Askarinam, Rodolfo Mundaca-Uribe, Farshad Tehrani, Emil Karshalev, Weiwei Gao, Liangfang Zhang, Joseph Wang, ACE2 Receptor-Modified Algae-Based Microrobot for Removal of SARS-CoV-2 in Wastewater, J. Am. Chem. Soc. 2021. https://doi.org/10.1021/jacs.1c04933
[7] Jan Labuda, Ana Maria Oliveira Brett, Gennady Evtugyn, Miroslav Fojta, Marco Mascini, Mehmet Ozsoz, Ilaria Palchetti, Emil Paleček, Joseph Wang, Electrochemical nucleic acid-based biosensors: Concepts, terms, and methodology (IUPAC Technical Report), Pure Appl. Chem. 2010, 82(5), 1161–1187. http://doi.org/10.1351/PAC-REP-09-08-16
Also of Interest
Recording of the 2021 IUPAC Analytical Chemistry Medal Lecture by Professor Joseph Wang
