Affordable ligand-based electrochemical detection of bacterial toxins

Lead Research Organisation: University of Birmingham
Department Name: Sch of Biosciences

Abstract

In this cross-disciplinary project we will work towards the development of affordable electrochemical sensors to monitor pathogenic concentrations of bacterial toxins in aqueous solutions. We will use a combination of of glycomics, material science, surface chemistry and microbiology to optimise electrode material composition and ligand display, and develop an easy, fast, portable and cheap way to detect bacterial toxins.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/M01116X/1 01/10/2015 30/09/2023
1790840 Studentship BB/M01116X/1 03/10/2016 25/04/2021 Carlos Guillen Posteguillo
 
Description In my project I'm aiming at improving the detection of the bacterium of cholera in water with an electrochemical sensor. For that, I'm working in two different branches of Chemistry: Organic Chemistry and Electrochemistry.

In Organic Chemistry my goal is the synthesis of organic molecules to chemically linking them with sugars, like glucose. Then, I use these molecules to form thin layers on top of conducting gold surfaces called electrodes; finally, I employ Electrochemistry to measure the difference of electrical current passing through the electrodes with and without layers of molecules on top.

After trying the synthesis of my first molecule for a few months , I failed so we decided to try a second compound. Nevertheless, I have designed a new method, to be attempted in the future, to overcome the problems experienced.

According to the different analytical techniques used, I managed to successfully synthesize the second molecule. But when I used it to cover the electrodes and perform Electrochemistry, the results were very poor and different to those reported in literature. I employed a very similar molecule to test if the problem was just related to its structure.

During the process of solving this issue, I realised how important is reading scientific literature discovering that with my method I wasn't obtaining a neutral molecule, but its cation; and its corresponding anion (trifluoroacetate) interferes in the formation of thin layers of organic molecules on gold surfaces. We made a small change in the method to have a different anion that would not affect the formation of layers of our cation on the electrodes. Initially I thought the results had not improved; but then I saw that our molecule (cation) forms such good and stable layers that I was using the wrong scale to analyse them. In fact our results were very good.

I have also successfully coupled the synthesized molecule with different sugars. But I have found difficult to purify them because of the formation of emulsions; I'm still working on this.

During the aforementioned process I have mastered many techniques used in organic synthesis (flush chromatography, thin-layer chromatography, lyophilisation, separating funnel, etc.) and learned how to use and interpret the results of some of the most important analytical techniques in Chemistry: NMR, MS, FTIR-ATR, HPLC, etc. In the area of Electrochemistry I have managed to study how organic molecules attach onto gold electrodes; and I have also calculated the degree of coverage of these molecules on the electrodes.

In my placement in Alicante I did electrochemical experiments that, when replicated in Birmingham, should help us to detect the toxin of cholera. And got into contact with a group with expertise in an analytical technique that could be of great use in the near future within our project (coupling of Electrochemistry and FTIR).
Exploitation Route Since our molecule adsorbs very well on gold electrodes, it could be linked to other molecules (other than sugars) that specifically interact with different substances in order to detect them: for example proteins and nucleic acids. This could be very useful to people working on electrochemical sensors of toxins, viruses, metals, etc. Similar molecules to the one I have synthesised could also be used for the modification of surfaces with organic molecules.

My molecule could also be incorporated into different types of electrodes (micro and nano-electrodes) to improve the sensitivity of electrochemical sensors. In the research group of the university of Warwick where I did a research placement they make micro and nano-electrodes. They could use it for sensing purposes.

Another possibility is using the molecule to cap gold nanoparticles. Nanoparticles are becoming more and more ubiquitous in many applications, like sensing and medicine, and the properties of the molecule I synthesised could be of interest for some of them.
Sectors Agriculture, Food and Drink,Chemicals,Environment,Healthcare,Leisure Activities, including Sports, Recreation and Tourism,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology,Security and Diplomacy

 
Description RSC Research Mobility Grant
Amount € 2,100 (EUR)
Funding ID Application M19-3484 for a Researcher Mobility Grant 
Organisation Royal Society of Chemistry 
Sector Charity/Non Profit
Country United Kingdom
Start 05/2020 
End 07/2020
 
Description Travel grant to attend the 47th IUPAC World Chemistry Congress
Amount £1,200 (GBP)
Organisation Royal Society of Chemistry 
Sector Charity/Non Profit
Country United Kingdom
Start 07/2019 
End 07/2019
 
Description 3 Minutes Thesis Competition (University of Birmingham) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact The 3 Minutes Thesis Competition (3MT) is a well-established competition held annually in hundreds of universities of more than 80 countries around the world. PhD students must present their Thesis project in just 3 minutes. It aims at improving the presentation and communications skills of the researchers, compelling them to explain their work in a language understandable to a broad audience in a brief period of time.

In the UK many universities hold local 3MT competitions, with the winners moving into a national final. In the case of the 3MT of the University of Birmingham, a jury composed of academics and non-academics determined the 10 best presenters, who moved into a final. The 10 finalists also had the opportunity to record a video that was uploaded to Youtube.

The final was attended by around 100 undergraduate students that had the opportunity to see a broad spectrum of the research done at the university. My video has been viewed on Youtube by 130 people to date.
Year(s) Of Engagement Activity 2019
URL https://www.youtube.com/watch?v=k1Q3BH78Vp4
 
Description Chemistry tutoring at a secondary school 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact I volunteer 1 h a week at the Dame Elizabeth Cadbury School, giving support to students who are struggling with their Chemistry courses in the year they face the GCSE exams.

This activity aims at helping students from less well-off families, improving their academic results but also encouraging them to stay in education and pursue a scientific degree.

The scheme has been run by this school for a few years, with a reported improvement in the results obtained by the school in those subjects where tutors are offered, such as Chemistry and Mathematics.
Year(s) Of Engagement Activity 2020