Rahina Mahtab | PubMed Health

PubMed2005

Probing DNA structure with nanoparticles.

Semiconductor nanoparticles, also known as quantum dots, are receiving increasing attention for their biological applications. These nanomaterials are photoluminescent and are being developed both as dyes and as sensors. Here we describe our "sensor" use of quantum dots to detect different intrinsic DNA structures. Structural polymorphism in DNA may serve as a biological signal in vivo, highlighting the need for recognition of DNA structure in addition to DNA sequence in biotechnology assays.

Animals↗

PubMed2004

Optical detection of thymine dinucleoside monophosphate and its cis-syn photodimer by inorganic nanoparticles.

The Watson-Crick DNA double helix is an averaged ideal of multitudinous natural sequence-directed local structural deviations. By effectively derailing normal cellular physiological processes, damaged bases can induce noncanonical irregularities in the local structure of DNA if not efficiently repaired. Pyrimidine bases, especially thymine, are prone to dimerization when exposed to ultraviolet light. A [2 + 2] photocyclo-addition between adjacent thymine bases predominantly produces the cis-syn photodimer. These lesions, implicated in skin cancer, bend DNA by approximately 30 degrees due to their structural and conformational changes. Such changes in molecular properties can be detected by differential quenching of CdS nanoparticle luminescence and by surface-enhanced Raman scattering spectroscopy on metal nanoparticle substrates.

Cadmium Compounds↗