Site‐Selective Labeling of Chromium(III) as a Quencher on DNA for Molecular Beacons
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Abstract Molecular beacons typically use organic molecules or nanomaterials as quenchers. Many transition‐metal ions have excellent fluorescence quenching ability, and the aim of this study was to recruit them as small quenchers in DNA detection. Cr 3+ has a slow ligand exchange rate, forming stable adducts with DNA. With its strong fluorescence quenching ability, the site‐specific labeling of Cr 3+ on DNA to form a new type of molecular beacon was investigated. The kinetics of quenching by Cr 3+ were measured for single‐ and double‐stranded DNA as a function of salt concentration, pH, and Cr 3+ ion concentration. The goal was to achieve a selective reaction with the single‐stranded but not double‐stranded regions. The reaction mechanism was also probed by adding adenosine triphosphate, revealing two Cr 3+ ‐binding modes: fast but unstable, and slow but stable. A partially complementary duplex was designed with a short polyguanine overhang, which, under optimal conditions, enabled selective labeling of the overhanging region with Cr 3+ . The resulting sequence was tested as a molecular beacon with a detection limit of 0.3 n m DNA and a saturated fluorescence enhancement of fivefold. With a 13‐nucleotide target DNA, the single mismatch discrimination of the beacon was 22‐fold. This study demonstrates the possibility of forming useful Cr 3+ adducts with DNA. Such adducts are not only useful for developing biosensors but also for constructing new materials.
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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 | 0.000 |
| 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 it