The unfolding of G-quadruplexes and its adverse effect on DNA-gold nanoparticles-based sensing system.

The adsorption of DNAs in G-quadruplex solution onto 13 nm gold nanoparticles (AuNPs) was studied through monitoring of the localized surface plasmon resonance (LSPR) absorbance of 13 nm AuNPs at 520 and 650 nm (A650/A520) in the solutions of three widely studied guanine-rich sequences, TBA(5'-GGTTGGTGTGGTTGG-3'), PW17(5'-GGGTAGGGCGGGTTGGG-3'), and PSO (5'-GGGTTAGGGTTAGGGTTAGGG-3'). It was found that the degree of adsorption of DNAs in Pb(2+) stabilized G-quadruplex (G-Pb(2+)) solutions is up to 93% after more than 5h of incubation. Furthermore, the lead concentrations in the solutions containing G-quadruplex and AuNP were analyzed by an inductively coupled plasma atomic emission spectrometer.

Double-functionalized gold nanoparticles with split aptamer for the detection of adenosine triphosphate.

A newly designed functionalization type for gold nanoparticles (AuNP) with split aptamer has been developed for the detection of adenosine triphosphate (ATP). The ATP aptamer was split into two parts with their 5' prime or 3' prime modified with thiol. Both the 5' SH and 3' SH modified strands for each split aptamer fragment were functionalized onto the same AuNP to construct double-functionalized AuNP-DNA conjugates.

Synthesis and characterization of β-CD-coated polystyrene microspheres by γ-ray radiation emulsion polymerization.

Polystyrene (PS) microspheres coated with β-cyclodextrin (β-CD) were fabricated via γ-ray-induced emulsion polymerization in a ternary system of styrene/β-CD/water (St/β-CD/water). The solid inclusion complex of St and β-CD particles formed at the St droplets-water interface can stabilize the emulsion as the surfactant. TEM and XPS results showed that β-CD remains on the surface of PS particles.