Diapositiva 1

Quantum dots and their interaction with DNA

05.04.2013.Nzev:

kolitel: Datum:Stanisavljevi Maja

Reg..projektu: CZ.1.07/2.3.00/20.0148Nzev projektu: Mezinrodn spoluprce v oblasti "in vivo" zobrazovacch technikQuantum dots history of synthesis

1980 Ekimov, Efros first description of quantum dots 1993 - Murray, Norris, Bawendi CdE(E=S,Se,Te) and other improvments like ZnS shellSemiconductor nanocrystals synthetized from II and VI or III and V elements of PSE. today-enviromental-friendly synthesis

CdTeZnS

Characteristics

small size 1-10nm absorbtion of light in wide range emmision range very narrow photostability and resistance to chemical degradation poisonous core and hydrophobic surface modification bioconjugation

DNA

1869 isolated by Swiss scientist Friedrich Miescher 1953 described DNA structure Watson and Crick 1962 they recieved Nobel prize for solving natures biggest secretDNA helix-two complementary and antiparallel polynucleotide strands

QDExperiment hypothesis:

Major groove 2.2 nmQD-GSH 2 nmDNA invisible for CE-LIFMix DNA and observe

Measurements conditions

CE-LIFCapillary lenght: ltot= 57 cm, leff = 50 cm, ID = 75 mBGE: 20 mM borate pH 9.2Separation: 20 kV, positive polarityInjection: 3.4 kPa for 20 secExcitation wavelenght: 488 nmEmmision wavelenght: 520 nmSample: QD-GSH and DNA from chicken in conc. of 1 mg/mL

QD-GSHMigration time (min)If (a.u)CE-LIF QD-GSHMigration time (min)If (a.u.)heated QDs 10 min at 50oCSize (nm)Intensity %ex = 380 nmem = 524 nmQD-GSH + DNA interaction through time

Migration time (min)IF (a.u.)

QD

QD

Concentraton of DNA (mg/mL)Height of peak

Time of migration (min)IF (a.u.)QD-GSH with different concentration of DNA

DNA 1 0.25 mg/mLDNA 2 0.50 mg/mLDNA 3 1.00 mg/mL

QD-GSH + DNA 1QD-GSH + DNA 2QD-GSH + DNA 3QD-GSHQD-GSH - dsDNA vs ssDNA

Migration time (min)IF (a.u.)QDsQDs + ssDNAQDs + dsDNANo complex

ssDNAdsDNAQD-GSH - hybridization of DNA

Hybridization of DNK: 99oC, 15 minMigration time (min)IF (a.u.)ConclusionsQDs and dsDNA interacts creating complex in shape of peak

Interaction peak grows through time and increasing DNA concentration

Complex is not created with ssDNA or hybridized dsDNA possible confirmation of QDs being caught in major groove

Some QDs with different capping agents

Thanks to :

Departament of chemistry and biochemistryJana Chomoucka for QD preparing

THANKYOUFORATTENTION!