ABSTRACT
A simple and sensitive method was developed for the detection of mercury ions with quartz crystal microbalance(QCM), based on the specific thymine(T)-Hg2+-T structure and gold nanoparticles. The gold nanoparticles were prepared by the citrate reduction method. In a self-assembled way, the particle surface was modified with the probe oligonucleotides which were partially replaced by 6-Mercaptohexan-1-ol to reduce the steric hindrance of hybridization. The sensitivity was optimized by the oligonucleotide with a strand length of 9bp and a T number of 7. The linear range was 5.0-100 nmol/L with a detection limit of 2.0 nmol/L. And Ca2+, Mg2+ and other metal ions had no significant interferences. This method was successfully applied for the detection of Hg2+in environmental water samples, with RSD less than 2.9% and recoveries of 97.3%-101.2%.
ABSTRACT
Aptamers are oligo-nucleotides which are selected by SELEX (systematic evolution of ligands by exponential enrichment) in vitro, it can bind protein or other small molecules with high specificity and affinity. Researches on aptamers have achieved much progress in biosensor, drug development and nano technology. This article has reviewed the researches and applications of aptamers in the past two years.
Subject(s)
Animals , Humans , Aptamers, Nucleotide , Biosensing Techniques , Methods , Drug Design , Nanotechnology , Methods , SELEX Aptamer TechniqueABSTRACT
A method combinating piezoelectric-biochip technique with cell culture technique in vitro has been developed. Piezoelectric cell-based chip (PCC) can continously monitor the behaviors of living cells attached to or spreaded on surfaces. The method measures the resonant frequency (f), the dissipation energy (D) and impedance (Z), in real time. These multi parameters can inflect information of cells qualitively and quantitively. This paper covers principle, materials and methods, results and discussion of the new technique, simultaniously indicates its application and trends.