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Objective To construct an electrochemical immunosensor for ultrasensitive determination of myeloperoxidase (MPO) .Methods The electrochemical immunosensor for M PO was prepared by modifying the electrode using Au-graphitized me-soporous carbon nanoparticles(AuNPs@ GMCs) hybrid and immobilizing MPO antibodies onto the glass carbon electrode surface . The effect of experimental parameters on the immunosensor and results comparison with ELISA were investigated .Results The immunosensor was sensitive to M PO with a linear relationship between 2 .000 and 300 .000 ng/mL and a correlation coefficient of 0 .999 ;the detection limit was 0 .5 ng/mL .The correlation coefficient of two methods was 0 .983 .Conclusion The immunosensor can be used for ultrasensitive detection of MPO .
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Objective To study the effects of AuNPs@PEG-AS1411 nanoparticles on radiosensitization of human uterine cervix cancer HeLa cells.Methods AuNPs were synthesized by citrate reduction method and then functioned with PEG and PEG-AS1411, respectively.CCK-8 assay and colon forming assay were used to detect the acute and chronic toxicity effects of AuNPs on HeLa cells, respectively.At the same time, clonogenic survival assay was applied to measure the cell survival rate of HeLa cells after exposure to AuNPs@PEG and AuNPs@PEG-AS1411 combined with X-ray radiation.The intracellular uptake of AuNPs@PEG and AuNPs@PEG-AS1411 in HeLa cells were detected by ICP-MS.Results The CCK-8 assay showed that AuNPs@PEG and AuNPs@PEG-AS1411 were not toxical on HeLa cells(P ＞0.05).But the clonogenic survival assay showed that AuNPs@PEG and AuNPs@PEG-AS1411 had toxicity on HeLa cells significantly after 10 d(t =4.38-11.60, P ＜ 0.05).AuNPs functioned with AS1411 could increase the cellular uptake of AuNPs.AuNPs@PEG and AuNPs@PEG-AS1411 both had significant radiosensitive effect on HeLa cells (F =7.90,48.23, P ＜ 0.05).The values of SERDo for AuNPs@PEG and AuNPs@PEG-AS1411 were 1.12 and 1.20, respectively, when the concentration of Au was 10 mg/L.Conclusions AuNPs@PEG and AuNPs@PEG-AS1411 could cause chronic toxicity on HeLa cells instead of acute effect.PEGylated AuNPs functioned with AS1411 could enhance the radiosensitivity of HeLa cells in vitro.
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A novel hydrogen peroxide sensor was fabricated by the seed-mediated growth method. First, polyethyleneimine(PEI) functionalized multiwalled carbon nanotubes(MWNTs) were used as growth scaffold on the glass carbon electrode ( GCE). Then, Au nanoparticles were electrodeposited uniformly as seeds. Finally, Pt nanoparticles ( PtNPs ) grew on Au nanoparticles to form Pt @ Au core-shell structure nanocomposite. A new type of electrochemical sensor based on Pt @ Au / PEI-MWNTs nanocomposites for detection of hydrogen peroxide was developed, and the designed Pt@ Au / PEI-MWNTs/ GCE was characterized by electrochemical methods and field emission scanning electron microscopy (FESEM). The Differential pulse experimental results showed that the modified electrode exhibited excellent electrocatalytic activity towards the reduction of H2 O2 with the wide linear range from 9. 2 ×10-8 mol/ L to 1. 3 ×10-3 mol/ L. The correlation coefficient was 0. 9994 and the low detection limit was 3. 1×10-8 mol/ L at the signal-to-noise of 3.
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Objective To explore the performance of the novel nitric oxide(NO) electrochemical microsensor based on Au nano-particles(nano-Au) modified glass-fiber .Methods With columnar glass-fiber as the substrate material ,the in-situ chemical seed-growth technology was adopted to fabricate one kind of electrochemical microsensor based on gold nanoparticles pole electrodes and the amperometric response method was used to investigate the various properties of the NO microsensor .Results This microsensor had high sensitivity response to NO ,its linear range was 7 .2 nmol/L -11 .7μmol/L(r=0 .998) with a detection limit of 3 .6 nmol/L .Conclusion A novel electrochemical microsensor based on nano-Au pole electrode was fabricated .The NO microsensor posseses high sensitivity ,wide linear range ,good reproducibility and excellent anti-interference ability .