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Glucose oxidase-catalyzed growth of gold nanoparticles enables quantitative detection of attomolar cancer biomarkers.

Liu D, Yang J, Wang HF, Wang Z, Huang X, Wang Z, Niu G, Hight Walker AR, Chen X - Anal. Chem. (2014)

Bottom Line: Although gold nanoparticle (AuNP)-based immunoassays offer high sensitivity, they were unable to quantitatively detect targets of interest most likely due to their very narrow linear ranges.In addition, the limit of detection (LOD) of prostate-specific antigen (PSA) of this approach (93 aM) exceeds that of commercial enzyme-linked immunosorbent assay (ELISA) (6.3 pM) by more than 4 orders of magnitude.The emergence of red or purple color based on enzyme-catalyzed growth of 5 nm AuNPs in the presence of target antigen is particularly suitable for point-of-care (POC) diagnostics in both resource-rich and resource-limited settings.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Medicinal Chemical Biology, Collaborative Innovation Center of Chemical Science and Engineering, and Research Center for Analytical Sciences, College of Chemistry, Nankai University , Tianjin, China.

ABSTRACT
Ultrasensitive and quantitative detection of cancer biomarkers is an unmet challenge because of their ultralow concentrations in clinical samples. Although gold nanoparticle (AuNP)-based immunoassays offer high sensitivity, they were unable to quantitatively detect targets of interest most likely due to their very narrow linear ranges. This article describes a quantitative colorimetric immunoassay based on glucose oxidase (GOx)-catalyzed growth of 5 nm AuNPs that can detect cancer biomarkers from attomolar to picomolar levels. In addition, the limit of detection (LOD) of prostate-specific antigen (PSA) of this approach (93 aM) exceeds that of commercial enzyme-linked immunosorbent assay (ELISA) (6.3 pM) by more than 4 orders of magnitude. The emergence of red or purple color based on enzyme-catalyzed growth of 5 nm AuNPs in the presence of target antigen is particularly suitable for point-of-care (POC) diagnostics in both resource-rich and resource-limited settings.

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Related in: MedlinePlus

Plots of A530nm (absorbance at 530nm) values of 5 nm AuNP solutions (8.3 nM) without and with the presenceof HAuCl4 (0.6 mM) and/or H2O2 (0.2mM). Red solid circle, 5 nm AuNPs solution incubated with both HAuCl4 and H2O2; yellow solid circle, themixture of HAuCl4 and H2O2; greensolid circle, 5 nm AuNPs solution incubated with HAuCl4; blue solid circle, 5 nm AuNP solution incubated with H2O2. The A530nm values foreach sample were recorded every 1 min by a Synergy 2 Multi-Mode MicroplateReader. Error bar: standard deviation of three independent measurements.
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fig1: Plots of A530nm (absorbance at 530nm) values of 5 nm AuNP solutions (8.3 nM) without and with the presenceof HAuCl4 (0.6 mM) and/or H2O2 (0.2mM). Red solid circle, 5 nm AuNPs solution incubated with both HAuCl4 and H2O2; yellow solid circle, themixture of HAuCl4 and H2O2; greensolid circle, 5 nm AuNPs solution incubated with HAuCl4; blue solid circle, 5 nm AuNP solution incubated with H2O2. The A530nm values foreach sample were recorded every 1 min by a Synergy 2 Multi-Mode MicroplateReader. Error bar: standard deviation of three independent measurements.

Mentions: As a startingpoint, we attempted to demonstrate the concept andinvestigate the impact of H2O2 on the growthof AuNPs. Different concentrations of H2O2 wereadded to a solution containing 5 nm AuNP seeds (8.3 nM, stabilizedby citrate) and AuCl4– (0.6 mM). Theresulting solutions were allowed to incubate at room temperature for20 min (see the dynamic process in Figure 1). The results in Figure 2a show that, asthe concentration of H2O2 increases, the solutionsgradually turn red. The color intensity is highly associated withthe concentration of H2O2. The obtained redsolutions can be monitored by UV–vis spectroscopy. As depictedin Figure 2b, the absorbance at around 530nm is intensified with an increased amount of H2O2. By collecting the absorbance at 530 nm for each solution, we foundthe intensity of the red color is in a linear range between 10 and100 μM (Figure 2c), suggesting the feasibilityof this probe to quantify the target of interest.


Glucose oxidase-catalyzed growth of gold nanoparticles enables quantitative detection of attomolar cancer biomarkers.

Liu D, Yang J, Wang HF, Wang Z, Huang X, Wang Z, Niu G, Hight Walker AR, Chen X - Anal. Chem. (2014)

Plots of A530nm (absorbance at 530nm) values of 5 nm AuNP solutions (8.3 nM) without and with the presenceof HAuCl4 (0.6 mM) and/or H2O2 (0.2mM). Red solid circle, 5 nm AuNPs solution incubated with both HAuCl4 and H2O2; yellow solid circle, themixture of HAuCl4 and H2O2; greensolid circle, 5 nm AuNPs solution incubated with HAuCl4; blue solid circle, 5 nm AuNP solution incubated with H2O2. The A530nm values foreach sample were recorded every 1 min by a Synergy 2 Multi-Mode MicroplateReader. Error bar: standard deviation of three independent measurements.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4066917&req=5

fig1: Plots of A530nm (absorbance at 530nm) values of 5 nm AuNP solutions (8.3 nM) without and with the presenceof HAuCl4 (0.6 mM) and/or H2O2 (0.2mM). Red solid circle, 5 nm AuNPs solution incubated with both HAuCl4 and H2O2; yellow solid circle, themixture of HAuCl4 and H2O2; greensolid circle, 5 nm AuNPs solution incubated with HAuCl4; blue solid circle, 5 nm AuNP solution incubated with H2O2. The A530nm values foreach sample were recorded every 1 min by a Synergy 2 Multi-Mode MicroplateReader. Error bar: standard deviation of three independent measurements.
Mentions: As a startingpoint, we attempted to demonstrate the concept andinvestigate the impact of H2O2 on the growthof AuNPs. Different concentrations of H2O2 wereadded to a solution containing 5 nm AuNP seeds (8.3 nM, stabilizedby citrate) and AuCl4– (0.6 mM). Theresulting solutions were allowed to incubate at room temperature for20 min (see the dynamic process in Figure 1). The results in Figure 2a show that, asthe concentration of H2O2 increases, the solutionsgradually turn red. The color intensity is highly associated withthe concentration of H2O2. The obtained redsolutions can be monitored by UV–vis spectroscopy. As depictedin Figure 2b, the absorbance at around 530nm is intensified with an increased amount of H2O2. By collecting the absorbance at 530 nm for each solution, we foundthe intensity of the red color is in a linear range between 10 and100 μM (Figure 2c), suggesting the feasibilityof this probe to quantify the target of interest.

Bottom Line: Although gold nanoparticle (AuNP)-based immunoassays offer high sensitivity, they were unable to quantitatively detect targets of interest most likely due to their very narrow linear ranges.In addition, the limit of detection (LOD) of prostate-specific antigen (PSA) of this approach (93 aM) exceeds that of commercial enzyme-linked immunosorbent assay (ELISA) (6.3 pM) by more than 4 orders of magnitude.The emergence of red or purple color based on enzyme-catalyzed growth of 5 nm AuNPs in the presence of target antigen is particularly suitable for point-of-care (POC) diagnostics in both resource-rich and resource-limited settings.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Medicinal Chemical Biology, Collaborative Innovation Center of Chemical Science and Engineering, and Research Center for Analytical Sciences, College of Chemistry, Nankai University , Tianjin, China.

ABSTRACT
Ultrasensitive and quantitative detection of cancer biomarkers is an unmet challenge because of their ultralow concentrations in clinical samples. Although gold nanoparticle (AuNP)-based immunoassays offer high sensitivity, they were unable to quantitatively detect targets of interest most likely due to their very narrow linear ranges. This article describes a quantitative colorimetric immunoassay based on glucose oxidase (GOx)-catalyzed growth of 5 nm AuNPs that can detect cancer biomarkers from attomolar to picomolar levels. In addition, the limit of detection (LOD) of prostate-specific antigen (PSA) of this approach (93 aM) exceeds that of commercial enzyme-linked immunosorbent assay (ELISA) (6.3 pM) by more than 4 orders of magnitude. The emergence of red or purple color based on enzyme-catalyzed growth of 5 nm AuNPs in the presence of target antigen is particularly suitable for point-of-care (POC) diagnostics in both resource-rich and resource-limited settings.

Show MeSH
Related in: MedlinePlus