Preparation of Luminol-doped Nanoparticle and Its Application in DNA Hybridization Analysis

Introduction The analysis of DNA sequence and DNA mutant detection play fundamental roles in the rapid development of molecular diagnostics and in the anticancer drug screening. Therefor many detection techniques of DNA sequence have been developed in recent years. These techniques mainly depend on the nucleic acid hybridization1 and their sensitivities are related to the specific activity of the label linked to the DNA probe. The degree of hybridization of probe to its complementary DN…

Preparation of Luminol-doped Nanoparticle and Its Application in DNA Hybridization Analysis

The dye‐doped silica nanoparticles can be used as nanobiosensors that are able to recognize and detect specific DNA sequence. In his paper, spherical nanosized luminol/SiO₂ composite particles have been synthesized with reverse micells via hydrolysis of tetraethyl orthosilicate (TEOS) in the microemulsion. The nanoparticles were modified with chitosan and used to label DNA, forming the DNA probe which was used to hybridize with target DNA immobilized on a PPy modified Pt electrode. The hybridization events were evaluated by electro generated chemiluminescence's (ECL) measurements and only the complementary sequence could form a double‐stranded DNA (dsDNA) with DNA probe and give strong ECL signals. A three base mismatch sequence and a non‐complementary sequence had almost negligible responses. Due to the large number of luminol molecules inside silica nanoparticles, the assay allows detection at levels as low as 2.0×10^?12 mol/L of the target DNA. The intensity of ECL was linearly related to the concentration of the complementary sequence in the range of 5.0×10^?12‐1.0×10^?9 mol/L.