Professor Tsuyoshi Minami of the University of Tokyo, Japan, is the first person to be awarded the IUPAC Emerging Innovator Award in Analytical Chemistry—an award that recognizes outstanding work undertaken by researchers who are at an early stage of their independent career.
Here he speaks with Dr. Vera Koester of ChemistryViews about his current research based on analytical and supramolecular chemistry, and how internationality and interdisciplinarity shaped him.
What does it mean to you to receive this IUPAC Emerging Innovator Award in Analytical Chemistry and being its first awardee?
I am very glad and very honored to receive this award.
If I am honest, I was surprised that the committee members chose my work to be honored. I find this very encouraging. Originally, I was not an analytical chemist. I started out as an organic chemist, so it is very kind to award me this recognition in analytical chemistry.
I started my own laboratory when I was 32 years old. I then changed research topics to something different from my supervisor, who was an organic chemist. I am trying to expand my field from the molecule to the device. Currently, my group is focusing on molecular design and synthesis of materials as well as the fabrication of chemical sensing devices.
You are working on chemical sensors based on organic thin-film transistors functionalized with molecular recognition materials, high-throughput analysis based on self-assembled optical sensor array systems. Can you please say a bit about your work?
I am trying to make, as you said, self-assembled chemical sensing systems. Basically, sensors are used to capture chemical substances, and then we can visualize this information as optical or electrical changes.
My research focus is the development of chemical sensors inspired by biological systems. Sensor arrays based on optical probes are inspired by the mammalian olfactory system. So let me briefly explain the olfactory sensory system: In our nose, we have around 400 scent receptors to detect over 100,000 odorant molecules. Based on pattern recognition, we can distinguish various types of flavors.
I decided to create an artificial system similar to that of our nose by using self-assembled molecular materials. In one of my approaches, I have focused on organic thin-film transistors (OTFTs) and optical sensor-based arrays. In the optical sensor arrays, we can fabricate an optical response pattern on a glass plate or on paper by using office printing technology. From the optical pattern, we can create a digital image that can be analyzed using machine-learning methods or extraction methods that we develop ourselves. In this way, we can distinguish or target different molecules simultaneously (e.g., chiral amines linked to drugs) or perform target analysis even in real samples (e.g., for environmental assessment).
You can imagine that to fabricate the various receptors or sensors of a single sensory system we have to make many types of receptor compounds. That means that we have to synthesize many organic compounds. My background is, as I mentioned, organic chemistry. Classical analytical chemists are not as interested in organic synthesis because it is not their expertise. I try to avoid synthesizing organic compounds that are too complicated. Ideally, the molecules can make chemical sensors by themselves via self-assembly in a flask, in a solution, on a glass plate, or on paper. So molecules can automatically and spontaneously make a chemosensor that detects a particular molecule, and we can see some color change or fluorescence change as a result of that. It has proven to be very useful in uniting organic chemistry with analytical chemistry. By this means, we can achieve more real-time applications.
One example is the development of a printed-paper-based chemosensor array system for various anion species, such as the herbicide glyphosate. What else can you say about your work?
My second topic of interest focuses on the realization of supramolecular devices. I am trying to expand my field from the molecule to the device.
In 1987, the Nobel Prize was awarded to Charles J. Pedersen, who described methods of synthesizing crown ethers. This was half a century ago, but even today and all around the world, there are not many devices based on supramolecular materials. So I wanted to use those materials as the primary components for applications in real society.
Supramolecular materials are architectures made up of molecules that can themselves assemble into larger constructs. As a platform for the device, I decided to use a transistor-based chemical sensor. Why did I select the organic transistor? As organic chemists, we can fabricate this material relatively easily. If we want to modify the molecules, we can do it by ourselves. Designing new functions or molecules is very attractive to me, so I remain an organic chemist at heart.
Such organic electronic devices, which are usually researched by electronic engineers, are used for flexible displays and electronic circuits. The organic devices have attractive features, e.g., switching profiles. From the point of view of a supramolecular chemist, organic thin-film transistors (OTFTs) can be referred to as “molecular self-assembled devices”.
With the OTFTs, the sensing part, transducer, and the data processing system can be placed on one chip. Very importantly, the organic devices can be fabricated using printing technology. I am not an electronic engineer, but I know how to use the printer; using the technology is relatively easy. From the viewpoint of a chemist, it is, therefore, relatively easy to fabricate such a device. As a result, I decided to use this kind of device for the chemical sensors.
Previously, for example, we have successfully detected lactate, glucose, or casein, a milk protein. I believe that such a flexible sensing system could be on a wearable. But it can also monitor environmental changes on-site.
My motivation is the hope that supramolecular materials can be used in real-world applications in this way.
What do you think are hot topics in the field of analytical chemistry?
Microfluidic systems for on-site sensing are hot topics in the analytical field. If we can combine analytical instruments with new materials in on-site devices, it’s a combination that can transform our quality of life.
Do you think we could reach a point where we can measure too much? I mean, if we are constantly tracking a lot of biometric parameters, couldn’t this become a problem?
Yes. There is a risk we will generate too much data. And privacy is also an issue here.
I think if you had the best data-driven diagnosis—if you collect a lot of information about the body to, for example, check its health and related conditions—it can be very helpful, such as in cancer prevention and treatment.
However, users need to be able to decide what they and others use and what they don’t use. They should have everything under their own control and be able to choose what they want to use. Science ethics is very important here. Protecting sensitive information is very important.
Where would you like to see the field growing in the next, say, 20 or 50 years?
In 20 years, I think we will see smaller-sized devices such as nanodevices, which means that the miniaturization of devices will be dramatically improved.
It’s a bit harder to predict what will happen half a century from now. Research will become even more interdisciplinary in the coming decades. I believe that the mixing of different fields can open up new aspects of analytical chemistry.
It is somewhat hard to predict which combinations will be most successful. Maybe organic chemistry is ideal, and exactly what I do will become the strongest field!
You have worked in the US, in the UK, and also, of course, in Asia. Did you experience differences between the people or in the labs?
Yes, during my Ph.D. I studied at the University of Bath in the UK as a visiting research student. Later, I was a postdoc and research assistant professor at Bowling Green State University, Bowling Green, OH, USA.
Coming to the UK was the first time I was outside of Japan, so it was exciting coming from what is maybe a rather isolated island to this European island. Especially in the US, it was very international with students from all around the world. After my research stay in the US, I joined a device laboratory at Yamagata University as an assistant professor. There, I was not among chemists. All discussions took place without chemical structures. It was a tough time for me, but also very inspiring.
Through the precious experience in this device group, I decided to expand my group to further broaden my research field, and because of my international experience, I try to accept international students and researchers in my group at the University of Tokyo.
Currently we are struggling with the coronavirus, but I like to collaborate with colleagues from other universities and I have students from Europe, Asia, the Arabian countries, and the US in my lab. In fact, I am trying to help mix the cultures and integrate different students from different backgrounds and with different mindsets. I believe that such international collaborative research encourages students and young researchers, just as I was encouraged in my thinking in the UK and US.
What role do scientific societies such as the Japanese Chemical Society or IUPAC play in this?
They are very important. IUPAC in particular connects chemists worldwide. The Chemical Society of Japan is involved in IUPAC.
I would say that the Chemical Society of Japan is increasingly opening up to other countries and is becoming more international. Originally, they organized their national conference only in Japanese, but now they have started to include English presentations and sessions. They especially encourage students to present in English. So if foreign scientists want to attend, that is relatively easy now.
How did you get interested in chemistry to begin with?
My mother was a chemist, so maybe that affected me that much in terms of career choice. My parents never said I should study chemistry. But they took me to museums and gave me books that inspired me. In the museum, the natural science things especially excited me.
When I was a kid, I wanted to know what materials around me, like a pen, are made of. Later I wanted to know more and more details, and then I decided to study chemistry.
What do you do in your spare time?
I like traveling and reading.
I wanted to attend the IUPAC Meeting in Canada, but unfortunately, we all could not go and had to attend it online. That is, of course, not the same. I like to experience the cultural differences in another country. It is also an exciting experience to meet other people. I am also enjoying our talk right now, but it is different to meet in person.
Let’s hope that we can soon see each other again and attend conferences.
Yes, hopefully. I think many people are getting vaccinated now, so hopefully, the situation will get better. It was nice meeting you and talking to you and hopefully, we can see each other face to face soon.
Thank you very much for the interview.
Tsuyoshi Minami, born in Saitama, Japan, in 1983, studied chemistry at Saitama University. In 2011, he obtained his Ph.D. from Tokyo Metropolitan University, Japan, under the supervision of Professor Yuji Kubo. During his Ph.D., he worked with Professor Tony D. James, University of Bath, UK. Between 2011 and 2013, Minami was a postdoctoral research associate at Bowling Green State University, OH, USA. In 2013, he was appointed to be a research assistant professor at the same university. In 2014, he moved to Yamagata University, Japan, where he became an assistant professor. He was appointed as a lecturer at the University of Tokyo in 2016. Since 2019, he has been an associate professor at the same university. Minami is also a visiting professor at Yamagata University, Tokyo Metropolitan University, and the University of Technology of Compiègne, France.
Tsuyoshi Minami’s research focuses on supramolecular analytical chemistry, self-assembled materials, gold nanoparticles, and organic transistors for sensing applications. Minami has discovered self-assembled optical sensor array systems to be promising candidates for the sensitive detection of analytes such as chiral amines, the herbicide glyphosate, saccharides in soft drinks, sulfur-containing amino acids, and toxic heavy metal ions without any synthetic burden. In the field of sensors, he designed and fabricated an extended-gate-type organic thin-film transistor for cross-hierarchical detection of various analytes across a wide range of sizes from small ions to biomacromolecules.
- Young Scientist’s Prize for the Commendation of Science and Technology by the Minister of Education, Culture, Sports, Science and Technology (MEXT), Japan (2020)
- The Chemical Society of Japan Award for Young Chemists (2020)
- ChemComm Emerging Investigators 2018 (Royal Society of Chemistry (RSC), 2018)
- The Japan Society for Analytical Chemistry Award for Young Researchers (2017)
- Tsukuru Minamiki, Tsuyoshi Minami, Yi-Pu Chen, Taisei Mano, Yasunori Takeda, Kenjiro Fukuda, Shizuo Tokito, Flexible organic thin-film transistor immunosensor printed on a one-micron-thick film, Commun. Mater. 2021, 2, 8. https://doi.org/10.1038/s43246-020-00112-z
- Koichiro Asano, Pierre Didier, Kohei Ohshiro, Nicolas Lobato-Dauzier, Anthony J. Genot, Tsukuru Minamiki, Teruo Fujii, and Tsuyoshi Minami, Real-Time Detection of Glyphosate by a Water-Gated Organic Field-Effect Transistor with a Microfluidic Chamber, Langmuir 2021, 37, 7305. https://doi.org/10.1021/acs.langmuir.1c00511
- Koichiro Asano, Yui Sasaki, Qi Zhou, Riho Mitobe, Wei Tang, Xiaojun Lyu, Masao Kamiko, Hikaru Tanaka, Akari Yamagami, Kazutake Hagiy, Tsuyoshi Minami, Detection of polyamines by an extended gate-type organic transistor functionalized with a carboxylate attached 1,3,4-thiadiazole derivative, J. Mater. Chem. C 2021, 9, 11690. https://doi.org/10.1039/D1TC01542G
- Qi Zhou, Mengqiao Wang, Shunsuke Yagi, Tsuyoshi Minami, Extended gate-type organic transistor functionalized with molecularly imprinted polymer for taurine detection, Nanoscale 2021, 13, 100. https://doi.org/10.1039/D0NR06920E
- Yui Sasaki, Riku Kubota, Tsuyoshi Minami, Molecular self-assembled chemosensors and their arrays, Coord. Chem. Rev. 2021, 429, 213607. https://doi.org/10.1016/j.ccr.2020.213607
- Zhoujie Zhang, Vahid Hamedpour, Xiaojun Lyu, Yui Sasaki, Tsuyoshi Minami, A Printed Paper-Based Anion Sensor Array for Multi-Analyte Classification: Application to On-Site Quantification of Glyphosate, ChemPlusChem 2021, 86, 798. https://doi.org/10.1002/cplu.202100041
- Xiaojun Lyu, Vahid Hamedpour, Yui Sasaki, Zhoujie Zhang, Tsuyoshi Minami, 96-well Microtiter Plate Made of Paper: A Printed Chemosensor Array for Quantitative Detection of Saccharides, Anal. Chem. 2021, 93, 1179. https://doi.org/10.1021/acs.analchem.0c04291
- Yui Sasaki, Soya Kojima, Vahid Hamedpour, Riku Kubota, Shin-ya Takizawa Isao Yoshikawa, Hirohiko Houjou, Yuji Kubo, Tsuyoshi Minami, Accurate chiral pattern recognition for amines from just a single chemosensor, Chem. Sci. 2020, 11, 3790. https://doi.org/10.1039/D0SC00194E
- Yui Sasaki, Koichiro Asano, Tsukuru Minamiki, Zhoujie Zhang, Shin-ya Takizawa, Riku Kubota, Tsuyoshi Minami, A Water-Gated Organic Thin-Film Transistor for Glyphosate Detection: A Comparative Study with Fluorescence Sensing, Chem. Eur. J. 2020, 26, 14525. https://doi.org/10.1002/chem.202003529
- Yui Sasaki, Satoshi Ito, Zhoujie Zhang, Xiaojun Lyu, Shin-ya Takizawa, Riku Kubota, Tsuyoshi Minami, Supramolecular Sensor for Astringent Procyanidin C1: Fluorescent Artificial Tongue for Wine Components, Chem. Eur. J. 2020, 26, 16236. https://doi.org/10.1002/chem.202002262
- Pierre Didier, Nicolas Lobato-Dauzier, Nicolas Clément, Anthony J. Genot, Yui Sasaki, Éric Leclerc, Tsukuru Minamiki, Yasuyuki Sakai, Teruo Fujii, Tsuyoshi Minami, Microfluidic System with Extended-Gate-Type Organic Transistor for Real-Time Glucose Monitoring, ChemElectroChem 2020, 7, 1332. https://doi.org/10.1002/celc.201902013
- Riku Kubota, Yui Sasaki, Tsukuru Minamiki, Tsuyoshi Minami, Chemical Sensing Platforms Based on Organic Thin-Film Transistors Functionalized with Artificial Receptors, ACS Sens. 2019, 4, 2571. https://doi.org/10.1021/acssensors.9b01114