What is the Difference Between SPR and LSPR?
🆚 Go to Comparative Table 🆚Surface Plasmon Resonance (SPR) and Localized Surface Plasmon Resonance (LSPR) are both phenomena related to the interaction of light with metallic surfaces. However, there are key differences between the two:
- Decay Lengths: SPR has longer decay lengths, while LSPR has shorter decay lengths. This makes LSPR less sensitive to interferences and more confined in sensing volume, resulting in higher sensitivity to molecular binding events.
- Sensitivity: SPR has a higher refractive index sensitivity than LSPR, but their sensitivity towards biomolecular binding events is similar due to the shorter electromagnetic decay length of nanoparticles compared to gold.
- Optical Hardware: LSPR requires less complex optical hardware, as no prism is needed to couple the light. This makes LSPR instruments smaller, more affordable, and more robust against vibration and mechanical noise.
- Temperature Control: LSPR does not require strict temperature control, simplifying the instrument setup.
- Refractive Index Sensitivity: LSPR is less sensitive to bulk refractive index changes, which can cause errors in experimental data.
In summary, SPR and LSPR are both useful for different applications, with SPR being more sensitive to refractive index changes and LSPR offering advantages in terms of instrument simplicity, cost, and sensitivity to molecular binding events.
Comparative Table: SPR vs LSPR
Here is a table comparing the differences between Surface Plasmon Resonance (SPR) and Localized Surface Plasmon Resonance (LSPR):
| Feature | SPR | LSPR |
|---|---|---|
| Decay Length | Longer | Shorter |
| Sensitivity | Higher | Lower |
| Refractive Index | Higher | Lower |
| Application | Measures reflectance change when material is attached to a single surface | Adapted for transmission measurements |
| Optimization | Structure and thickness of the thin metal film must be optimized for the SPR-based sensor | Size and shape of the plasmon particles must be controlled for the LSPR-based sensor |
| Potential for Practical Use | High, but requires more complex systems | High, with simpler systems that are more advantageous for miniaturization |
| Advantage | Higher sensitivity | Ease of construction and simplicity |
SPR is the resonant oscillation of conduction electrons at an interface between negative and positive materials, while LSPR is a collective electron charge oscillation in metallic nanoparticles excited by light. The key difference between SPR and LSPR is that SPR decay lengths are comparatively longer and more sensitive, whereas LSPR decay lengths are comparatively shorter and less sensitive to interferences.