Hello all. I am working on a project to hopefully detect/measure hydrogen peroxide. My device is going to be an oral health monitor and I originally wanted to replicate the functionality of a glucose monitor. I believe I have bitten off more than I can chew however. I went down a rabbit hole of Arduino based potentiostats ( Building a Microcontroller Based Potentiostat: A Inexpensive and Versatile Platform for Teaching Electrochemistry and Instrumentation | Journal of Chemical Education (acs.org))but as I learn more, I feel like those might be overly complex if all I want to measure is Hydrogen peroxide. Does anyone have any suggestions or a good starting place?
I'm pretty new to arduino but I'm no scrub. I just don't know what I don't know and I'm spending a lot of time going down rabbit holes. Thanks in advance for any guidance.
A good place to start is by reading recent research articles on hydrogen peroxide measurement and sensing, and researching industrial solutions to the sensing problem. Quantitative measurements are neither trivial nor cheap.
Here is one industrial sensor offering: https://www.wpiinc.com/products/instruments/analyzers/analyzers/biosensors/hydrogen-peroxide-sensors
Those are TWO different rabbit holes. To measure, you need a calibrated standard. Can you make or obtain such a standard?
May I ask why then glucose monitors are so inexpensive? In my mind i figured it could be cheap since a glucose monitor also is essentially just a h2o2 detector? I'm sure I'm missing something there right? Also thank you for the resource I had not thought of looking at industrial solutions schematics.
Are you saying to obtain like a standard curve of resistance for different concentrations of H202? I would have figured that I wouldnt need that as h202 sensing should be well characterized from glucose sensing right? Like if I read technical information of some glucose sensor and see the voltages they apply, is that enough information? Sorry if that doesnt make sense. I understand sensor theory but the circuitry/application gives me headaches.
Nothing could be further from the truth. I see why you are having trouble with this project.
Hmm. Can you elaborate? From my understanding, when glucose in the blood comes into contact with lyphollized enzymes on a test strip, the enzymatic reaction produces h2o2, which is detected electrochemically with a set of electrodes getting a specific voltage. What am I missing? Not trying to be rude but I'm not sure what all there is to a glucometer outside of that.
It is ridiculous to trivialize the 60 to 70 years of concentrated research and development that has gone into the relative ease of monitoring blood glucose these days, but then, it is a multi-billion dollar health problem.
I posted a link to an H2O2 electrode above. Have fun with your project.
If that is the type of sensor you have, then you still have to calibrate it to some standard in order to MEASURE.
Thank you for your input, and I appreciate the link to the H₂O₂ electrode—it will be very useful for my project. I understand and deeply respect the decades of research and development that have gone into making blood glucose monitoring as accurate and user-friendly as it is today. The advancements in this field have been extraordinary and are a testament to the dedication and expertise of countless researchers and engineers.
My intention was not to trivialize these achievements but to abstract the fundamental principles of H₂O₂ detection that are used in glucose meters to explore applications in a different context. I'm aware that replicating the reliability, accuracy, and sophistication of commercial glucose meters in a DIY project is not feasible, nor is it my goal. Instead, I'm interested in applying the electrochemical principles of H₂O₂ detection in a more rudimentary form to investigate other areas where these methods could be beneficial.
I hope this clarifies my approach, and I'm here to learn and share in the spirit of collaboration and exploration that makes forums like this so valuable. Thanks again for your insights—they're an important reminder of the incredible work that goes into medical device development and the impact it has on lives around the world.
That's not how it works. Can you point me to where you saw that?
Most glucometers today do use an enzymatic reaction to do some electrochemistry, but it's not a special meter that's sensitive only to one thing. It's just measuring redox potential that's being affected by that enzymatic reaction. Even if it was detecting hydrogen peroxide, it would be determining the concentration based on oxidation potential. That's easy if peroxide is the only variable. The stuff inside your mouth is very very complex. Hydrogen peroxide is only one of many things that contribute to the redox potential you would read.
It's a completely different story to a blood sample in a tiny capillary.
Thank you for taking the time to explain some differences to me. I read it in a Bioinstrumention book. I have preliminary data showing the efficacy of my enzymatic cocktail coverting ATP to h202 and I dont have any reason thus far to suspect that anything else in salivia would throw off my numbers past calibration. So if my math is right, I should be able to detect h202 the same way. Maybe im incorrectly using the words detect and measure but "it would be determining the concentration based on oxidation potential. " is exactly what I'm looking for but I just need a refrence on what a schematic like that might look like. I'm a tissue engineer so circuits and arduino stuff isnt my wheel house.
So are you talking about trying to take a saliva sample? Or do something in the mouth? Still, that redox environment is so much more complicated than blood.
Because your sensor detects anything that changes redox potential, that's the thing that complicates it. It's not about your enzymatic reaction. It's that there's no way to make it only sensitive to hydrogen peroxide.
In the case of the glucometer it's like trying to hear one person talking in a room full of people whispering. In the case of Saliva it will be like trying to hear one person talking from the other side of a Motorhead concert.
I'm an analytical chemist.
Ahhhh ok I think I see what you mean. I wont be taking a saliva sample, but taking a swab of of the gum liine/ tooth. But truthfully, I dont even need it to operate under those conditions. I'm just showing efficacy of some underlying scientific principles. So far, I have shown that I can extract ATP from bacteria consistantly, and that I can convert pure atp to H202 (pure ATP so even farther from the truth). So I understand that IRL the complexity would muddy the waters so to speak, but Im interested purely in that redox reaction and how to set it up. So I want to show a device that, when a random concentration of h202 is placed on the electrodes of a SPE, accuractly displays the correct concentration. Does that clarify or did it make it more confusing? I appreciate your patience.
There are bacterial test strips for food products that work like this. I can't remember right off what it was called but I used to work for a food safety company and I remember seeing their brochure.
But there's was colorimetric I think. There are some good colorimetric ways to measure hydrogen peroxide. Those would be better than just measuring redox because they'd actually be specific to hydrogen peroxide.
unfortunatley my team is locked into this project and were kind of too far to look back. I recognize the practical limitations of our device. There are luciferase based assays that do what we want with better accuracy if I'm being honest. We just need to finish this for senior design. So I need to make a device that that I can put in a screen printed electrode, and dropper drop some h202 of various concnetrations, and the screen tells tells me roughly what the concentration is. All proof of concept stuff.
This was a really great analogy to help understand some key principles. Thanks
Yeah, that was it. That's what the food safety thing did. I remember now that you say it. It was measuring the signal from a luciferase reaction to measure the H2O2.
One scientist to another, but this thinking is the problem that gets you to where Elizabeth Holmes is right now.
When something doesn't work, we don't figure out how to fake it. Real science leads to all sorts of dead ends. Our response to them can't be deceptive or the whole of science loses.