How a Flutter offline-first app reshapes UV data entry in a phytochemistry lab. 200 ms validation, on-the-spot IC50, traceable Excel export — and free downloads for Android and Linux.
Picture this. You are at the bench. Nitrile gloves on, hands faintly smelling of methanol, working through your twentieth DPPH tube of the morning. The spectrophotometer reads 4.2. The value is saturated, so wrong, but you do not know that yet. You scribble "4.2" in your notebook and move on.
Three weeks later. You transcribe into Excel. You rebuild the curve. And there it is, obvious: that 4.2 point should never have been in the dataset. The calibration drifted off the rails by step 4. Half the run needs redoing.
This story has happened to so many people in phytochemistry that it stopped being funny. It is exactly the scenario PhytoNote was built to make impossible.
The solution, in three moves
PhytoNote is a small pocket-sized app, built for one job: entering UV measurements in the lab. When you read the absorbance on the spectrophotometer, you type the value on your phone (or your Linux tablet). Three things happen at once:
- The value is saved. No "OK" button. If the app crashes or the battery dies, nothing is lost.
- The value is validated. Within 200 milliseconds the app checks if it sits in the acceptable range, if it is near saturation, if it deviates too much from the control. It shows a traffic light: 🟢 OK, 🟡 watch out, 🔴 problem. If it is red, the tube is still there on the bench, and you can redo it immediately.
- The math moves on. The calibration curve refreshes with each point. By the time you finish the session, the IC50 (or equivalent in standard) is already computed. No need to open Excel that evening.
Eight built-in assays
PhytoNote covers the eight most common UV assays in phytochemistry:
- DPPH, ABTS: to measure how antioxidant an extract is, using synthetic free radicals.
- FRAP: to measure reducing power, that is, the ability to transfer electrons.
- CAT (TAC): total antioxidant capacity via the molybdenum complex.
- TPC: total phenolic content (Folin-Ciocalteu method).
- TFC: total flavonoid content (aluminium chloride).
- ANTIBAC: to test whether an extract inhibits bacterial growth (96-well plate microdilution, CLSI protocol).
- ANTIINF: to test anti-inflammatory effect through BSA denaturation.
Each assay knows its reference standards (ascorbic acid, Trolox, gallic acid, quercetin, ciprofloxacin, diclofenac), its reading wavelength, its acquisition plan. You pick the test, the extract, the plant, the number of replicates. The app generates the dilution sequence automatically.
Multi-sheet Excel export
When the session is done, one tap generates an .xlsx workbook that contains everything: session metadata, calibration curve with slope and R², raw measurements per concentration and replicate, intermediate calculations, final regression equation. If a reviewer or an audit comes back to your run a year later, it is all there, in a format anyone can open.
Download the app
PhytoNote v1.0.1 is freely downloadable (GPL-3.0 license) on GitHub. Pick the build that matches your device:
| Platform | Download | Size | Pick this if you have… |
|---|---|---|---|
| Android arm64-v8a | app-arm64-v8a-release.apk | 8.0 MB | A recent Android phone (Snapdragon 8xx, Exynos 9xx+, MediaTek Dimensity) — this is what you need 95% of the time. |
| Android armeabi-v7a | app-armeabi-v7a-release.apk | 7.6 MB | An older Android phone (Android 7+, Snapdragon 400-600). |
| Android x86_64 | app-x86_64-release.apk | 8.1 MB | An Android emulator on PC, or some tablets with Intel chips. |
| Linux | phytonote_1.0.1_amd64.deb | 8.3 MB | An Ubuntu 22.04+ or Debian 11+ machine. |
How do you know if your Android phone is recent? If you bought it in 2019 or later, it is almost certainly arm64-v8a. If you are unsure, download that version first; the install will cleanly refuse if it is incompatible, and you can try armeabi-v7a with no risk.
To install on Android: open the APK from your file manager, allow installation from "unknown sources" if Android asks, and that is it.
To install on Linux: double-click the .deb in your file manager, or from the terminal:
sudo dpkg -i phytonote_1.0.1_amd64.debSource code and issues: github.com/Saliha-BOUAOUDA/PhytoNote.
Going further
If you want to understand what these assays actually measure, I am publishing a series of short articles on the technical concepts that come up most often in analytical phytochemistry. Not all of them are published as you read this, but here is the list:
- What is an IC50?
- DPPH, ABTS, FRAP: antioxidant assays in 5 minutes
- Total phenolics and the Folin-Ciocalteu method
- Antibacterial microdilution and the 96-well plate
- Linear calibration and R²: the statistical basics
- Aqueous vs methanolic solutions in extraction
Citing PhytoNote in your work
Bouaouda, S. (2026). PhytoNote (version 1.0.1) [Computer software]. Zenodo. https://doi.org/10.5281/zenodo.20376869