Spotlight: Exploring the potential of graphene-enhanced electrochemical biosensors with Chiara Zanardi

Chiara Zanardi’s research journey has been deeply intertwined with exploring the electrocatalytic properties of graphene oxide and related materials, a quest she embarked upon back in 2015. She has teamed up with Vincenzo Palermo from the CNR Institute for Organic Synthesis and Photoreactivity (ISOF) in Bologna, Italy, to develop electrochemical sensors designed to detect important biomarkers within biological fluids.

These activities were part of the Graphene Flagship’s Spearhead Project Chemsens between 2018 and 2020, and resulted in flexible sensor devices in the following phase of the Graphene Flagship from 2020.

Zanardi now holds the position of Full Professor of Analytical Chemistry at the Ca'​ Foscari University of Venice and is also an associate member of the ISOF-CNR. Here it is her interview.

What’s your research focus?

My research activities revolve around electroanalysis, with a primary focus on developing sensors and biosensors for the quantification of meaningful analytes in the environment, biological fluids and food items. These sensors are designed based on the principle that certain analytes trigger specific electrochemical reactions. When a target molecule interacts with the sensor's surface, it can lead to changes in electron transfer processes or the generation of electric current that can be measured.

For instance, I have developed sensors that detect glucose and lactate in sweat [1-4], identify drug abuse [5,6] and, more recently, I have worked on sensors to quantify organic contaminants in water. This implies the development of electrode coatings based on innovative materials, with precise selectivity and detection limits.

In which way can 2D materials boost sensors?

My experience was particularly directed to the use of graphene related materials with oxidized moieties on their surface. These can interact with target analytes present in solution. Additionally, they offer the potential for stable anchoring of bioreceptors (such as enzymes or other biomolecules), thereby enhancing the interactions’ selectivity.

Furthermore, these 2D materials can be directly deposited onto different surfaces or used to create self-standing films [4] and inks [3], enabling the direct realization of conductive devices possessing the desired geometry.

I read that you are also working on sensors array based on artificial intelligence. How can AI help in your field?

Imagine a sample with a complex chemical composition, much like many real systems that must be analysed. The typical approach normally is to use several sensors, each capable to detecting a single analyte. However, trace amounts of a potentially dangerous analyte could go undetected, overshadowed by other analytes present in larger amounts. We are trying to verify whether the use of AI can analyse data coming from a massive array of electrochemical micro-scale sensors, spot the possible presence of trace amount of a certain analyte and obtain more reliable results.

Has the Graphene Flagship influenced your career path in some ways? If yes, in which way?

Thanks to the Graphene Flagship, I met numerous scholars, each contributing to the research on 2D materials with their own expertise. Additionally, I could engage with companies facing real-world issues and showing interest in driving research from proof of concept to the market. The discussions in which I participated expanded my perspective beyond sensor-related research, often sparking new inquiries within me about the properties of 2D materials and their potential for innovative applications.

What are your plans for the future?

There is still a huge amount of work to be done in the development of effective sensors that can assist in our lives. Examples include the early monitoring for the onset of a heart attack or detecting the presence of specific contaminants in a water pipeline before it reaches the tap.

The COVID-19 emergency has highlighted the importance of using point of care devices for the continuous monitoring of clinical parameters, even outside of dedicated clinical structures. The opportunity to have a simple and rapid means of monitoring various chemical parameters in our daily lives can help us enhance our lifestyle and keep track of our health without relying on specific laboratory facilities.

References

1. Poletti, Fabrizio et al. “Electrochemical sensing of glucose by chitosan modified graphene oxide” Journal of Physics: Materials 3 (2020): 014011 https://iopscience.iop.org/article/10.1088/2515-7639/ab5e51/meta
2. Poletti, Fabrizio et al. “Continuous capillary-flow sensing of glucose and lactate in sweat with an electrochemical sensor based on functionalized graphene oxide” Sensors and Actuators B, 344 (2021): 130253. https://www.sciencedirect.com/science/article/pii/S0925400521008224
3. Silvestri et al. “Bio-responsive, Electroactive and Inkjet-printable Graphene-based Inks” Advanced Functional Materials, 21 (2022): 2105028 https://onlinelibrary.wiley.com/doi/full/10.1002/adfm.202105028
4. Poletti, Fabrizio, et al. "Graphene‐Paper‐Based Electrodes on Plastic and Textile Supports as New Platforms for Amperometric Biosensing." Advanced Functional Materials32 (2022): 2107941. https://onlinelibrary.wiley.com/doi/full/10.1002/adfm.202107941
5. Maccaferri, Giulio et al. “Highly sensitive amperometric sensor for morphine detection based on electrochemically exfoliated graphene oxide. Application in screening tests of urine samples” Sensors and Actuator B, 281 (2019): 739. https://www.sciencedirect.com/science/article/abs/pii/S0925400518319397
6. Zanfrognini, Barbara et al. “Preliminary evaluation of the use of a disposable electrochemical sensor for selective identification of Δ⁹-tetrahydrocannabinol and cannabidiol by multivariate analysis.” Microchemical Journal 183 (2022) 108108. https://www.sciencedirect.com/science/article/abs/pii/S0026265X22009365