Topic
Spectroscopy research, explained
9 open-access spectroscopy studies, each with a flashcard deck and a quiz.
- Charged amino acids absorb past 250 nm
A 67-residue protein with no aromatic side chains still absorbs from 250 to 800 nm because Lys/Glu charge-transfer transitions create Protein Charge Transfer Spectra.
- In-cell NMR of a DNA G-quadruplex and ligand
A parallel d(TG4T)4 G-quadruplex remains NMR-visible and long-lived in Xenopus oocytes, but ligand 360A can hide the complex on the NMR timescale.
- PDMS vials measure PAH activity in polluted soil
Thin PDMS coatings of several thicknesses in glass vials reach equilibrium with soil PAHs so HPLC-fluorescence concentrations can be converted into chemical activities.
- 2D IR indexing maps hIAPP helix-to-sheet kinetics
Paired 13C18O labels report dihedral angles: monomeric hIAPP is partly helical at L12A13, then oligomers lose helix and fibers form β-sheets.
- UV chemometrics quantify two COVID-era drugs at once
CLS, PCR, PLS and GA-PLS models resolve overlapping UV spectra of montelukast and levocetirizine, with GA-PLS best (R2 > 0.99) and Latin-hypercube validation plus greenness scores versus HPLC.
- Gold dithiolene radical holds a 21 μs spin qubit
Neutral [Au(adt)2] stores the unpaired electron on the ligand, giving phase-memory times up to 21 μs in low-spin solvents and 1.44 μs when doped into a nickel molecular semiconductor.
- Al3+ lights up Ag/Au clusters to sense fluoroquinolones
Dithioerythritol Ag/Au nanoclusters aggregate with Al3+ and then report ciprofloxacin, norfloxacin and enrofloxacin by ratiometric fluorescence down to a few nanomolar.
- Wide-band TA maps an Fe(II) four-state cascade
Femtosecond TA from 370–1200 nm resolves 1PALCT → 3PALCT → 3MC → 5MC decay in an iron amido chromophore, including a ~100 fs NIR CT signature.
- Paper titanyl sensor sees H2O2 vapor at 0.04 ppb
Ammonium titanyl oxalate on cellulose turns yellow as a Ti(IV)–peroxide complex, detecting hydrogen peroxide vapor down to about 0.04 ppb without fancy instrumentation.