1. Data Input

Upload a file with two columns: first column = [H]₀ / mM, second column = F₀ / F.
A header row is allowed and will be ignored automatically.

2. Set Parameters

Kd
Fix
Dissociation Constant Host-Dye (range: 0.1 nM – 100 mM)
Stoichiometry (n)
Fix
α (Static Quenching)
Fix
α = complex residual brightness (range 0–1; log slider)
kq·τ0 / mM⁻¹
Fix
kq·τ0 = Dynamic quenching parameter (range 0–100; log slider)
Weighted Fitting
Optional weighting for heteroscedastic Stern–Volmer noise.

3. Analysis

Tip: click a point in the residual plot to exclude or restore it from the fit.
Stern–Volmer Model:
\[ \frac{F_0}{F} = \frac{1 + k_{q}\cdot\tau_{0}\cdot\left([H]_{0} - \frac{x}{n}\right)} {1 - \frac{x}{[I]_{0}}(1-\alpha)} \]
Bound complex concentration:
\[ x = \frac{b - \sqrt{b^{2} - 4[I]_{0}\,n\,[H]_{0}}}{2} \qquad \text{with} \qquad b = [I]_{0} + n[H]_{0} + K_{d} \]

4. Report

Fit report will appear here after update.
Publication Export Settings
Journal theme:
Publisher-inspired preset; exact figure rules can vary by journal.
Width: mm Height: mm DPI:
Axis/frame scale: Font scale:
Stats block: Residual analysis:
Fitting Strategy:
1. Fix n: Use integers based on realistic interaction; experimentally determined with ITC or Job Plot.
2. Fix α: Check whether F₀/F plateaus at high [H].
3. Free Fit: Let Kd and kq·τ0 solve via regression.
4. Residuals: Ensure random scatter around zero.
Hongbin Wu AG Cordes / TU Dortmund hongbin.wu@tu-dortmund.de