A facile and sensitive electrochemiluminescence biosensor for Hg2+ analysis based on a dual-function oligonucleotide probe.

In this study, a sensitive electrochemiluminescent (ECL) biosensor for the detection of Hg(2+) was easily prepared by self-assembling mercury-specific oligonucleotide on the surface of gold nanoparticles (AuNPs) modified indium tin oxide (ITO) electrode. A conformation change of the oligonucleotide from linear chain to hairpin occurs upon the binding of Hg(2+) through thymine-Hg(2+)-thymine coordination. The dual-function oligonucleotide serves as the probe to Hg(2+) but also a carrier of signal-generating molecules, [Ru(bpy)2(dppz)](BF4)2. It was estimated that one oligonucleotide was able to load with eight ECL signal molecules; a ratio of four or five oligonucleotides per gold nanoparticle was obtained basing on the calculation with surface density. Without tedious multiple-labeling procedures and special modification of oligonucleotide probe for signal transduction/amplification, a detection limit of 5.1 pM Hg(2+) was outstanding from the interference of other ten metal ions. Results of spiked water samples were in good agreement with that obtained by atomic fluorescent spectrometry.

The complete mitochondrial genome of Asiotmethis jubatus (Uvarov, 1926) (Orthoptera: Acridoidea: Pamphagidae).

The complete mitochondrial genome of Asiotmethis jubatus (Uvarov, 1926), which was collected from the Xinjiang Uygur Autonomous Region of China, is reported here. It is 15,669 bp in length and contains 72.3% AT. All Asiotmethis jubatus protein-coding sequences start with a typical ATN codon, excluding cox1 and nad6. The usual termination codon (TAN) and incomplete stop codons (T) were found from 13 protein-coding genes. All tRNA genes could be folded into the typical cloverleaf secondary structure, excluding trnS(AGN) which forms another structure. The sizes of the large and small ribosomal RNA genes are 1315 and 852 bp, respectively. The AT content of the A + T-rich region is 81.9%.