Preliminary Study of CdTe Quantum Dots Applied in DNA Sensors

Abstract

With the development of molecular biology and genetic technology, target DNA detection and transition of genetic information are becoming increasingly significant, and electrochemical biosensor gains many concerns in direct detection of target DNA due to the advantages, i.e. simple mechanism, reliable result, low-cost process, sensitive and selective method for genetic detection. a novel biosensing system was presented and investigated based on electrochemical and DNA techniques, and the nano-scale semiconductor CdTe quantum dots (QDs) was firstly introduced to sensing system to investigated its electrochemical effect and properties, the sensing probe with structure of gold electrode (AuE)-CdTe quantum dots (CdTe QDs)-gold nanoparticles (AuNPs)-single strand sensing probe (ssDNA) was fabricated with layer-by-layer self-assembly method. The electrochemical properties and sensing ability of the probes were characterized and determined via cyclic voltammetry (CV) method. Obvious differential redox peaks current were revealed when the fabricated AuE/CdTe QDs, AuE/CdTe QDs/AuNPs, and AuE/CdTe QDs/AuNPs/ssDNA was examine by CV method, respectively. The sensing probe showed high sensitivity and specificity when the complementary target DNA and the target DNA with one-base-mismatch were determined, respectively. The current results indicated that the fabricated DNA biosensor has great potentials in detecting special DNA sequences via DNA technology.