Stern–Volmer Analysis

Fit Stern–Volmer responses with the same layered model system and publication export workflow.

1. Data Input

Upload CSV or Excel

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.

[H]₀ / mM

F₀ / F

[I]₀ / mM

2. Model Presets

Binding model

Quenching mode

3. Set Parameters

K_d

Fix

Dissociation Constant Host-Dye (range: 0.1 nM – 100 mM)

Stoichiometry (n)

Fix

For 1:1 Exact and 1:1 Hill Approximation models, n is fixed to 1. For Hill Empirical, this control becomes the Hill exponent h.

α (Fractional Dimness)

Fix

α = relative brightness of the bound state (0–2; α > 1 means bound state is brighter).

k_q·τ₀ / mM⁻¹

Fix

k_q·τ₀ = dynamic quenching parameter (0.0001–100; log slider).

Weighted Fitting

Optional weighting for heteroscedastic Stern–Volmer noise.

4. Fit and Update

Stern–Volmer Model:

\[ \frac{F_0}{F} = \frac{1 + k_q\tau_0[H]_{\mathrm{free}}}{1-\theta(1-\alpha)} \]

Binding / Occupancy Model:

\[ \theta = \frac{([I]_0+[H]_0+K_d)-\sqrt{([I]_0+[H]_0+K_d)^2 - 4[I]_0[H]_0}}{2[I]_0} \]

Free host term:

\[ [H]_{\mathrm{free}} = [H]_0 - \theta[I]_0 \]

5. Fit Report

Model output

Fit summary, parameter estimates, and quality notes will appear here after you update the model.

6. Final Figure

Preset and layout

Journal theme: Style:

Journal theme and Column now both trigger the matching preset values. Width stays tied to the active journal/column preset even when stats block or residual analysis is changed.

Manual sizing and output

Width: mm Height: mm DPI:

Axis/frame scale: Font scale:

Stats block: Residual: Log X-axis

Fitting Strategy:
1. Start from the two-layer preset that best matches your expected binding model and quenching behavior.
2. Use simpler constrained presets first, then unlock more parameters only if residuals remain structured.
3. For independent n-Sites, consider fixing n initially. For Hill fits, treat h as empirical.
4. Ensure residuals scatter randomly around zero before interpreting the fitted mechanism.

Hongbin Wu AG Cordes / TU Dortmund hongbin.wu@tu-dortmund.de