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In this paper, a nonenzymatic glucose biosensor based on perovskite LaTiO3–Ag0.2(LTA) modified electrode was presented. The morphology and the composition of the perovskite LaTiO3–Ag0.2 nanomaterials were characterized by using scanning electron microscopy (SEM) and X-ray diffraction (XRD) respectively. The LaTiO3–Ag0.2(LTA) composite was investigated by electrochemical characterization using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under optimal conditions, CV and chronoamperometry (I-t) study revealed that, compared with the bare glassy carbon electrode (GCE), the modified electrode showed a remarkable increase in the efficiency of the electrocatalytic oxidation of glucose, starting at around +0.70V (vs. Ag/AgCl). The prepared sensor exhibited a high sensitivity of 784.14µAmM−1 cm−2, a low detection limit of 2.1×10−7 M and a wide linear range from 2.5µM to 4mM (R=0.9997). More importantly, the LTA modified electrode was also relatively insensitive to commonly interfering species such as ascorbic acid (AA), uric acid (UA), dopamine (DA) in high potential. Moreover, the nonenzymatic sensor was applied to the determination of glucose in human serum samples and the results were in good agreement with clinical data. Electrodes modified with perovskite nanomaterials are highly promising for nonenzymatic electrochemical detection of glucose because of their high sensitivity, fast response, excellent stability and good reproducibility. [ABSTRACT FROM AUTHOR]

Aim: To predict the probable genomic packaging signal of SARS-CoV by bioinformatics analysis. The derived packaging signal may be used to design antisense RNA and RNA interfere (RNAi) drugs treating SARS., Methods: Based on the studies about the genomic packaging signals of MHV and BCoV, especially the information about primary and secondary structures, the putative genomic packaging signal of SARS-CoV were analyzed by using bioinformatic tools. Multi-alignment for the genomic sequences was performed among SARS-CoV, MHV, BCoV, PEDV and HCoV 229E. Secondary structures of RNA sequences were also predicted for the identification of the possible genomic packaging signals. Meanwhile, the N and M proteins of all five viruses were analyzed to study the evolutionary relationship with genomic packaging signals., Results: The putative genomic packaging signal of SARS-CoV locates at the 3' end of ORF1b near that of MHV and BCoV, where is the most variable region of this gene. The RNA secondary structure of SARS-CoV genomic packaging signal is very similar to that of MHV and BCoV. The same result was also obtained in studying the genomic packaging signals of PEDV and HCoV 229E. Further more, the genomic sequence multi-alignment indicated that the locations of packaging signals of SARS-CoV, PEDV, and HCoV overlaped each other. It seems that the mutation rate of packaging signal sequences is much higher than the N protein, while only subtle variations for the M protein., Conclusions: The probable genomic packaging signal of SARS-CoV is analogous to that of MHV and BCoV, with the corresponding secondary RNA structure locating at the similar region of ORF1b. The positions where genomic packaging signals exist have suffered rounds of mutations, which may influence the primary structures of the N and M proteins consequently.