High Sensitivity of Plasmonic Microstructures near the Transition from Short-Range to Propagating Surface Plasmon
Bibliographic record
Abstract
The optical properties of Au triangles with 700 and 950 nm and 1.8 μm edge length and of microhole arrays with a 3 μm periodicity show a strong absorption peak highly sensitive to refractive index with excitation in the Kretschmann configuration of surface plasmon resonance (SPR). This absorption peak is due to a SPR phenomenon only present with microstructures of micrometer length, as demonstrated with SPR active materials, Au and Ag; but absent in SPR inactive materials, TiO x N y and Ag triangles covered with a thin film of silver oxide. The Au triangle arrays were exhibiting: 1) two transmission minima at λ = 525 and 800 nm with low refractive index sensitivity and 2) a transmission maximum near λ = 600 nm exhibiting a high sensitivity to bulk refractive index for the triangles with an edge length of 950 nm (1993 nm/RI) and 1.8 μm (1038 nm/RI). This is a significant improvement of the sensitivity compared to nanoparticles and is near the sensitivity of SPR on a smooth film. The transmission minima at λ = 800 nm was also present in microhole arrays in a Au film, but of reduced intensity as the size of the hole decreases. Moreover, the microhole arrays with smaller holes also presented a strong transmission minimum around λ = 600 nm, with a similar wavelength, bandwidth and sensitivity as SPR on a smooth gold film. Lastly, the response measured for the formation of a monolayer on the triangle arrays results in a large shift of the SPR response of 13 ± 3 nm, which correlates to a short penetration depth of 24 nm. Triangle arrays investigated in the present configuration could significantly improve SPR biosensing by increasing the measured response from a binding event and could decrease the temperature drift due to a lower bulk refractive index sensitivity.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".