ELFT HÍRADÓ

[Szeminárium koordinátor <pusztai.tamas AT wigner.hun-ren.hu>]

SZFI SeminarVeres, MiklósHUN-REN Wigner RCP SZFI Reading DNA hybridization 
from a single vibrational frequency: could alkyne Raman probes become a real 
diagnostic alternative?Tuesday, 3 November 2026, 10:00, KFKI Campus, Bldg. 1, 
2nd floor, Conference RoomDetecting DNA hybridization and single nucleotide 
variants (SNVs) at defined loci is central to molecular diagnostics. Yet most 
readout schemes rely on fluorescence, enzymatic amplification or sequencing. 
We recently showed that the stretching frequency of an alkyne group, 
introduced into an oligonucleotide probe as 5-ethynyl-2′-deoxyuridine, 
reports the hydrogen-bonding pair of the tagged base. Ab initio calculations 
and high-resolution Raman measurements indicate distinct shifts for matched 
and mismatched duplexes, allowing discrimination of clinically relevant 
genetic mutations. We then extended the concept to an RNA virus target 
sequence using engineered alkyne reporters.The effect is small, about one 
wavenumber, and measured in the bio-orthogonal silent region with spontaneous 
Raman scattering at sub-millimolar concentrations. Turning it into a 
practical method therefore requires solving three problems: precision, 
instrumentation and sensitivity. In this talk I review our work on each. I 
discuss the analysis of noisy spectra. It shows that hybridization can be 
detected within seconds through changes in band intensity and width. I 
present a dispersion-free, single-channel Raman technique in which the 
spectral components of a broadband laser are modulated at different 
frequencies, suited to high-resolution measurement of narrow bands. I show 
polymer-microparticle-supported gold and silver SERS substrates that reach 
detection limits down to 10⁻¹¹ M. Finally, I present tip-enhanced Raman 
results on alkyne-labelled DNA, which reach single-modification localization 
but also show how strongly the plasmonic environment perturbs the alkyne 
frequency. Minden érdeklődőt szívesen látunk! - Everyone is welcome to 
attend.Tamás Pusztaipusztai.tamas AT wigner.hun-ren.hu