ABSTRACT
A new type of amperometric immunosensor for the determination of naphthalene based on self-assemble) layer-by-layer technique was reported. The preparation procedure of such a sensor was characterized and the operation conditions, such as the pH value of supporting solution, incubated temperature and time were studied by cyclic voltammetry. Under the optimized working conditions, the current response of the immunosensor) was proportional to the concentration of naphthalene in the range of 0.5-100 μg/L with a detection) limit of 0.08 μg/L(r=0.9986). This method was applied to the naphthalene detection in river) water) samples and the recovery was ranging in 94.3%-107.0%. The reported immunosensor exhibited high sensitivity and long-term stability for naphthalene detection, and was easy to be prepared and regenerated.
ABSTRACT
The gold hollow nanospheres have been synthesized by sacrificE-template method and the obtained sample has been characterized by TEM, SEM and XRD. The amperometric formaldehyde gas sensor was assembled with gold hollow nanospheres as the active electrode material and 1 mol/L KOH solution as electrolyte. The equation of linear regression(y=16.63x+4.063×10-7, r=0.9989)between the oxidation current(y(A))and the concentration of formaldehyde(x/(mol/L)) was obtained at the formaldehyde concentration in the range of 0 to 2.23×10-6 mol/L. The sensitivity of the sensor with gold hollow nanospheres as active material increased by about 70% compared with the sensor made of nanoparticles which had the same gold-loading in the work electrode, this method exhibits an advantage of decrease in the cost of the noble metal. This kind of sensor shows potential application in formaldehyde gas detection in this range due to its excellent sensitivity, stable response and good linear relationship.
ABSTRACT
Objective For realizing the simultaneous detection of multiple pathogens,by looking for a method with a combination of the new gene chip detection system based on nano-gold with the technology of restriction endonuclease without PCR.Methods Helicobacter pylori,Mycoplasma pneumoniae,Chlamydia trachomatis,Candida albicans,Ureaplasma urealyticum,and EB virus were selected as the experimental targets.Endonuclease Hha Ⅰ was selected as tool enzyme.After bering digested by Hha Ⅰ,the digested fragments of samples were tailed with poly-A.The samples were then detected by the gene chip detection system based on nano-gold.Both specific and common probes were used in the hybridization.The coincidence rate of the detection results between the new constructed chip test and the fluorescence quantitative PCR test in 168 clinical samples was examined.The stability and sensitivity of chips detection were also checked.Results The new constructed nano-gold-baesd gene chip combined with restrictive enzyme digestion without PCR could be used to detect the target pathogens.The coincidence rate of the chip detection test and fluorescence quantitative PCR test in 168 clinical samples was 89.2%.Chip detection results showed that the stability of chips detection was 100% and the sensitivity was 50pmol/L.Conclusion The newly constructed nano-gold-baesd gene chip combined with restrictive enzyme digestion without PCR can be widely applied in the simultaneous detection of Mycoplasma,Chlamydia,fungus,virus and bacteria.It shows a bright prospect in increasing the throughput of identifieation of pathogene.