Polymorphism in Cysteine Adsorption on Au Surfaces: Zwitterions versus Uncharged Molecules
Bibliographic record
Abstract
The adsorption of amino acids on coinage metal surfaces has been of interest for a range of biological applications. Core to the advancements of these applications is understanding the structure of the adsorbed molecules and the state they are present in. Cysteine, the focus of this study, has been studied extensively, both experimentally and theoretically. Here, density functional theory (DFT) and molecular dynamics are used to examine the different adsorption modes of the cysteine monomer on an Au(111) surface in vacuum. Dimeric structures and their influence on the adsorption mode of the individual molecules are also considered. We find that the most stable monomeric binding mode is an unconventional zwitterion the ammonium group is formed by do- nation of the mercapto hydrogen. Moreover, we observe the transformation of neu- tral adsorbed molecules to unconventional zwitterion through direct or indirect proton transfer. On the other hand, conventional zwitterions are unstable in monomeric form, either in gas phase or adsorbed structure calculations.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".